Pros: Solid build quality: Mounting brackets for 2.5" and 3.5" drives feel super solid (I came from a Corsair 300R with plastic mountings that constantly broke.
Filtration: I always look for cases with filtered intakes and this case has filtration on front, bottom and top.
Cable routing: There was always a gasket where I needed it and I ended up with my best looking build yet.
Included fans: I am never too optimistic about included fans but the (2) included 140's seem on par in terms of noise-to-airflow with the Noctua NF-P14 FLX that I added (I moved all of these fans to the front grill).
Noise: This case is SUPER quiet! There is noise dampening material on the back wall and vibration cancellation rubber throughout. But the key to this low noise comes from unimpeded airflow across big fans, this allows for low RPMs (low noise) to keep things really cool.

Cons: These are all very minor, but I have to come up with something.

No noise dampening in front panel: The front panel is just light plastic, it would have been easy to add dampening material on this inside that faces the front fans.
Thumb screws: These screws are very tight making it uncomfortable to loosen them the first time (told you my complaints are minor)
Motherboard standoffs: My box DID inlcude enough standoffs, so no issue there. However, some of these standoffs are shared between all board shapes and could have been pre-mounted to save me a little work.

Other Thoughts: Transferring my build from my old Corsair 300R to this case was truly painless (if you don't count the thumbscrews). This case gives me comparable cooling with much lower temps and better noise. I feel like my mix of air and pre-built water cooling is really under-utilizing this case (I could fit a small child in the remaining space). As Fractal claims, this case would be perfect for someone who wants to do a custom/semi-custom watercooling setup on an ATX board. All you have to consider is if two 2.5" drives, three 3.5" drives, and 7 rear PCI cuttouts will be sufficient for your masterpiece. If so, buy this case without concern; it will do exactly what you need.

My Specs
i7-4790k OC @ 4.2 GHz
Corsair H60 cooler with Push/Pull mounted to rear outlet
16 GB RAM @ 1866 MHz
970 GTX MSI Gaming Ed. OC @ 1450 MHz
256 GB Samsung 850 EVO
1 TB WD Black
Rosewill Challenger 650 W PSU

Pros: It is VERY easy to work in, there is tons of room and tie down points. The entire build process took me maybe half an hour once i had disassembled my old pc.
The window is huge and looks stunning
tons and tons of fan mounting areas.
Very study
Excellent build quality
The Velcro straps are amazingbasically 100% dust proof.
a bunch of room on the back side panel for cables

Cons: It isn't as quiet as i expected it to be (i have an air cooled system). Still more quiet than my last case, but i would have liked it to be dead silent. I guess i would have needed to get the Be Quiet case or something if i really wanted that tho.
I would have liked more USB ports.

Other Thoughts: I would still buy this if i had another chance. I love the way it looks, and although i wasn't sure if i would like the white fans/expansion slots i quickly fell in love with them (I have a black/blue color scheme). Definitely worth $90, and it should last me a very very long time. Can't wait until i have the money to water cool :)

Pros: The noise dampening really works, only sound i hear coming out of it is on the side without it.

Cons: They could have put the noise dampening material on the front panel and the windowed side around the window, bought noise dampening foam to get around this issue.

Other Thoughts: If you truly value silence go with the non windowed version, but some of us want to show off a $1800 build

Pros: I managed to get this on sale during black Friday but that wouldn't stop me from buying another one at normal retail. There a lot of advantages to having a case of this size. Note that this marketed a mid tier case, however it is pretty wide. Not that I am complaining but it's just something to note.

- Spacious interior with amazing cable management
- Thumbscrews on both panels make life easier
- Lots of locations to put fans/radiators
- Hidden Drives behind the motherboard
- Cable management made easier thanks to the cable ties in the back
- Soundproofing panels on the top and behind the motherboard
- Built in filters on the front and bottom of the case

Cons: None. This is an amazing case. Definitely worth the buy

Other Thoughts: Like I mentioned before, it is important to note how wide this case is and just how spacious it is. I was surprise to find so much space after completing my build. I bought this case with the intent to watercool in the near future. I am currently running an air cool rigged but I can't wait to try water cooling.

The only reason why I didn't give this 5 stars is because of the blue led on the power button and the lack of a filter on top, but these are nit-picky observations. I would seriously consider buying this case if you are looking to water cool your rig or if you just want lots of free space.

Pros: -No drive cages
-looks nice and sleek
-lots of room for airflow
-easy cable management

Cons: my only cons with this case is the side panels were annoying to get back on and the case is way bigger than expected. I feel like their should be an easier way for fractal to mount the side panels. And no it was not my cable management they weren't sticking out blocking it, it was the weird locking system they have on the top and bottom side of the case. Would have been better if they had some kind of rail system you just slide it through instead of this weird push lock stuff, because if you don't get them all in at the same time you have to take it off and do it again. Really annoying!

Other Thoughts: I would recommend it just know that the side panels are tedious to get back on.

Pros: -Clean design
-Easy build process
-Decent cable management
-Plenty of room for expansion and high end cooling

Cons: -Sound dampening material on side panel makes it hard to close without spending extra time on cable management. Mine is currently bowed out a touch because I'm terrible at cable management.

Other Thoughts: -Bought to replace my 5 year old Antec 1200.
-Very happy with the switch... excellent use of space!
-Would buy again. Going to spend more time on getting my cables stowed properly.

Pros: -Large Interior Space
-Quiet
-Easy to modify
-Plenty of room for fans
-included all hardware necessary.
-easy to have a clean wire setup.

Cons: I had no issues with my case.

Other Thoughts: I ordered the one without the side glass, didn't see the option at first. I wish I didn't miss it. I am looking to get the side panel now. I will update on whether I can order it from Fractal Design or not.

MSI 970 MOBO
AMD FX9370k Black cooled with Hyper D92
Radeon HD7790 (next upgrade)
1 TB mechanical drive

Pros: - Space! Lots of it
- Clean cable management
- Access to motherboard from reverse side (made it easier to install custom CPU cooler after mobo was already mounted in place. This was a definite plus
- Fans are dead silent. Bought 3 additional GP-14 fans to complete the front panel with 3 and bottom of the Case with 1
- Excellent air flow

Cons: - Really disappointed with the Window panel. I've only had this for a little over 2 months, and the panel looks like it's been attacked by a pack of Wild Animals. I use a lot of caution when opening the case, but somehow the window panel is still covered in scratches.
- I paid more for the windowed panel to show off my interior case parts, but now I'm regretting it as the cheap plastic window shows multiple scratches. Can I replace the windowed panel with the regular version under warranty? I doubt it's covered by warranty :(

Other Thoughts: All-in-all, it's a great case. I wish they had used Tempered Glass for the window panel. I paid more for the Windowed version and now wish I had just gotten the regular version of this case. Minus 1 Egg for this oversight on Fractal Design's part.

Pros: I did not buy this here as Neweggs site was causing me a ton of issues when I would try and check out.

My Define S did not come with a viewing window. The case is very sturdy it just has a feel of quality(specially for $80) All hardware was included. There is a ton of room work with this bad boy. Was a bit longer then I expected and had had to move my Corsair H55 to the center of the front case in stead of the bottom ill elaborate more in other thoughts) Comes with two fans, Both are pretty silent and move a lot of air. Make sure to pick up a couple more for more air flow. I love that the HDD now goes on the right side panel cleans a lot of things up quite nice. A ton of space for cable management. Over all a great product buy buy buy also very silent.

Cons: Bottom right Mobo stud location was cross threaded. Took the provided stud that was pre installed in the case and swapped it over and slowly worked at the cross threaded hole and was able to straighten it out enough to just use that in the place of the brass stud(they are brass right?) Not even worth taking a Egg off for it.

Maybe come with more fans?( being nit picky here ha!)

Other Thoughts: Keep in mind this case is a bit longer then some of the other cases on the market( I was running a Zalman x2 case) I got this case mainly for the Air flow and wanted me to move my H55 radiator and fan from the back of the case to the front to keep it as a intake and not create any turbulence. However the lines where just a bit short on letting me run the radiator on the bottom slot on the front intake So need to run it in the center and have the 140mm fan up in the top slot on the front of the case.

Also make sure your Mobo has enough system fan slots as there is no place to put a fan controller in.

Pros: While this isnt any flashy "wow your friends" case, it is great. It does exactly as it was intended to. All my PC parts are housed happily inside, at decent temperatures, and minimal noise.

Cons: Does not have as many bells and whistles as the R4 case (my father has the R4, and it is quite nice.) but for a slightly above average PC build budget, this case is great.