Pros: **Significantly cools an i7-4790K. Temps for Folding at Home were mid 80s and Prime95 at 100. After installing this temps for FAH was low 50s and Prime95 was low 60s.
**Quiet fan. The only time I hear it is when the Fan RPM is over 1000 under load. During normal operation you cannot hear it at all.
**Comes with one fan and a second fan can be installed

Cons: **I'm not a fan of the colors but this is being nit picky
**Not for overclocking

Other Thoughts: Installation is easy enough to figure out. For the Intel CPUs you have to unmount your mobo to install the back plate. If you have a case that has the rear case motherboard cutout you won't need to dismount the mobo. Make sure you have a case that will support the heatsink's height. I would highly recommend this heatsink to those looking for an air and quiet solution. It's definitely not for those looking to overclock though. For the i7-4790k simply overclocking it to 4.4GHz brought back the high temps the Intel heatsink was providing.

Pros: Easy to install
Keeps my CPU cool - 40-50C at normal load and up to 75C under stress

Cons: none

Other Thoughts: I would recommend this product

Pros: You get a Noctua fan (that's a big plus). Heat sink actually has decent thermal transfer. Fits many CPU types. Very quiet.

Cons: Ugly. A little heavy. Only fits into full-width cases.

Other Thoughts: Highly recommended. This went into a gaming rig to cool an Intel i7-5930K 140W CPU. It does so with ease.

Pros: - well packaged
- excellent installation instructions
- easy to install
- it fit in my Fractal Design R5 case, but just barely. This case is wider than most cases at 9" but it uses more than normal space behind the MB.

Cons: - BIG!
- Thermal paste was hardened rock solid making it unusable. Without thermal paste I couldn't install. I got a replacement that was okay.

Other Thoughts: - I haven't built a new machine in years. Since I couldn't install the unit I can't comment on its cooling ability (i7-6700K CPU). Greatly disappointed I have to wait to build my new computer just because of the solid, unusable thermal paste. A $7 item stopping the build of a $1,000 machine. I RMA'd the unit and ordered a new one. Hopefully the thermal paste will be good in the new one. I contacted Noctua support but got no answer as of this review.

UPDATE
I was able to install the replacement unit. I'm not impressed with the cooling ability. I'm running an i7-6700K with no OC on an ASUS Sabertooth Z170 S MB in a Fractal Design R5 case. CPU runs about 34 degrees C at idle but temp rises very quickly under load. Under full load using the AIDA64 stability test, CPU temp stabilized at 43 C but individual cores averaged in the high 70's. Fortunately I don't expect heavy usage at that level so the cooler will be good enough.

Pros: Qualty feel to it
Packaged beautifully
Lots of accessories
Easy to install
Meeps my i5 6600 nice and cool

Cons: None at all.

Other Thoughts: Definitely recommended
Solid buy
Cant go wrong with Noctua

Pros: - Super quiet, even at full speed.
- Short enough to fit a mid sized ATX case.
- Decent price for the quality.

Cons: - In the box instructions were lacking, but still gave it 5 stars because the Noctua website makes up for it.
- Fan does not indicate on it which direction the fan pushes the air, be sure to test it before you finish your computer build.

Other Thoughts: - If you are looking to overclock your CPU, this is a good mid level choice.
- Be sure to check the max CPU fan size your computer case will take.

Pros: -solid construction
-premium fan, the color grows on you once you see it in person
-six heat pipes
-well packaged
-a great overall product if they can work on their quality control

Cons: Hearing so much about their quality I was very disappointed to find bent fins on the bottom right corner opposite the side on which the fan was mounted. The shipping and manufacturer's boxes were not damaged which tells me it came from their facility in this condition.While it doesn't seem like the fan's performance will suffer much if at all, it wasn't something I expected from a company like Noctua given their reputation. Since I it may not affect temps much, it isn't worth the hassle of returning time but I'll be more likely to shop other brands in this bracket now. If an entry level cooler that costs less than half as much can arrive without damage, so should one from a company such as Noctua.

Other Thoughts: I have three more builds to complete this and I'll likely go with a premium fan and heat sink from another company.

Pros: Very easy install. Makes things cooler :)

Cons: None

Pros: Killer thermal solution !

Cons: That's my point: In the process of trying to determine which Noctua model was appropriate for new Skylake build w/ i7-6700K cpu, the more I searched Newegg listings for product info, the less sense it made.
Humor me and do a search for "noctua nh-u12s". Note the various 'skylake high prices', the various discriptions noting absent detailed specifics and the 'sold by ____' .
Hmmm ! Newegg (as seller) has a NF-U14S2 (same unit w/140mm fan) priced fairly at $78. Further, searches showed similar for their fans.

Pros: Very quiet even if you add another Noctua fan. Installation is painless -- I was able to do it in 10 minutes.

It cools my Intel Core i7-5775C down to 22 C at rest and about 42-45 C at 100% load.

Cons: It is about 163 mm high so some ITX cases might not fit it.

Other Thoughts: Overall a positive experience from this product. This was the first air cooler I installed in a long time and it is pretty good (I usually just use one of the Corsair AIO closed loop solutions).