Pros: Easy to setup; Great speed; Right size. Fits everywhere.

Cons: - Nothing significant until it stopped working. Just when I needed it most!

Other Thoughts: - Despite the many negative reviews in different boards, I decided to go ahead and buy the NUC.
My Set Up was
- RAM 2 x 8G G.SKILL Ripjaws 260-Pin DDR4 SO-DIMM DDR4 2133 (PC4 17000)
- Primary drive, SAMSUNG 850 EVO M.2 500GB SATA III 3-D Vertical Internal SSD Single Unit Version MZ-N5E500BW
- Secondary drive, Samsung 850 EVO 500GB 2.5-Inch SATA III Internal SSD (MZ-75E500B/AM)
I picked every part from Intel's approved list.

It was working one moment, next moment I got a Windows 10 BSD: WHEA_UNCORRECTABLE_ERROR
Unfortunately, the computer died 30 days after Newegg's warranty expired.

Unfortunately, I cannot recommend this product with this many people experiencing same issue.

Pros: Small
Packs a lot of power for its size
Quiet

Cons: The BIOS is immature (four updates have been released since November)
The hardware has problems (Intel recently released a hardware change notice for the motherboard)
The NUCs are incredibly finicky about what kind of RAM they'll work with. They won't work with DIMMs built with Hynix DRAM modules.

Other Thoughts: The Intel NUCs are a neat idea, a small, powerful computer based around a laptop CPU. You get plenty of power in a small package and even after adding RAM and an SSD you're still not out too much money. This is a great desktop replacement if you don't need expansion slots or high-end graphics. You can expand the memory to 32Gb and on the SYH model you can install a Samsung 950 NVMe drive (which are screamingly fast) and a standard 2.5" SSD, or even a mechanical drive, but why bother since SSDs are so cheap these days.
The problem with the Intel NUCs is that the hardware and the software haven't matured yet. Intel has released four BIOS updates since November of 2015. Additionally there are stability problems when attempting to use the Skylake NUCs with RAM based upon chips from SK Hynix, which is a major problem since Hynix is, according to Wikipedia, the second largest manufacturer of DRAM chips in the world. The NUCs are incredibly finicky with what kind of DRAM they will accept. Intel recently released a hardware change notice related to the capacitors used by the memory controller which might fix this problem. Other people have reported problems with the NUCs destroying themselves by not properly adjusting the fan speeds thus causing the CPU to overheat. I would recommend the SYH model (which has space for a 2.5" SSD) over the SYK model (M.2 drive only) because the larger size of the SYH model allows for more space for heat to dissipate. If you're interested in this kind of hardware you might want to wait a few months before purchasing one so you can get one with the revised motherboards.

Pros: Small size, lots of ram.

Cons: I got this to replace my shuttles as hosts for virtualization. Ran OK for just over a month, now they (yes I bought more than one) wont even boot or finish a re-install. I put the latest bios on, reverted back, even went to a previous version before the on that came on it. These are turds wrapped up in a shiny metal box. So, now I have 96gb of ddr4 ram to find a home for. Thanks intel....

Other Thoughts: I would NOT recommend these to anyone unless they like tossing their money in the trash.

Pros: Powerful unit, really awesome specs for such a small device.
Compatible with OpenELEC appliance OS for HTPC usage (with KODI)
Built in M.2 port, IR, DisplayPort, and USB 3.0

Cons: BIOS has a bad history so far. (Still has problems with current 033)
My first unit blew up pretty hardcore a few weeks after I got it.
Memory compatibility issues.
Updating the BIOS can be a nightmare.
Standard 2.5" slot is very difficult to remove a drive out of.

Other Thoughts: After tinkering with this unit for a few weeks and getting OpenELEC running smoothly on it, the unit decided to blow up. I was notified it has bit the bullet because for some reason it started dumping massive voltage into the managed network switch it was hooked to, and that switch threw health alarms all over my network. After powering it odwn manually, the unit would no longer come back online, only showing a solid blue light on the front but no video output, no BIOS post screen, no HDD activity. Intel confirmed the unit was toast and requested I initiate an RMA through NewEgg.

The RMA was initially for a replacement, but I was told it takes 10 days AFTER the bad unit is received to even start shipping the replacement, which is insane. However, NewEgg support allowed me to swap it to a refund and float the $400 to buy another unit now and overnight it, and offered to refund me the shipping costs. I'm still going to be out nearly $400 for weeks until they refund the defective unit.

These units are fantastic when they work properly. If I didn't realize how great they were I'd probably not bother to risk replacing it with a second unit.

UPDATE 4/2016! Replacement unit has been working fine with latest BIOS. Adding back an egg!

Pros: The unit is still a great alternative to office pc. Very fast with M.2 or regular 2.5 SSD.

Cons: The bios out of the box was version 28. The unit initially booted then became a brick after saving minor bios changes. No boot. No Video, No Bios splash screen. So I though it was done. I have Kingston Hyperx 2133 DDR4 modules in it and a Crucial 500gb m.2 too. I booted the unit and set the time and date, and enabled the features I wanted on the unit then saved the changes and restated it and the NUC would not post after any of the bios changes.
Since intel has been having bios issues with this model they said not to use the USB recovery method with the .bio file on a flash drive. I believe they stated this with the .33 version and the .36 version. So I used the .39 bio file opened the unit back up and moved the jumper to recovery and recovered the bios with the .39 file and everything now works. I have not had any issue with any NUC prior to these Gen 6 units. I have built 50 plus gen 5 units that never had any bios issue's. This is really a step back as far as I am concerned. The verdict is out if this device rushed to quickly to distribution. Only time will tell.
I am watching this unit like a hawk to make sure it will be stable to use for my customers.

Other Thoughts: Be careful on which m.2 drive you buy the crucial MX 200 2260 is to short. It will not work I had to use a support bracket to use it. Should have looked at the specs. The older gen 5's used the 2260's just fine. My BAD.

Pros: See my previous review

Cons: None

Other Thoughts: I was able to install W10 Pro from a USB dongle with zero issues.

Pros: - Compact with good thermal design, the fan is not loud at all, unlike Gigabyte brix, which is super loud.
- Iris 540, which I feel is much more better than HD 520. Can play games with high quality.
- 2 slots without any price added

Cons: - the bundle has a incompatible RAM.

Pros: The NUC itself is great, the Avexir RAM bundled with it is not. Do not buy the bundle and buy different RAM instead.

Cons: The bundled RAM, Avexir 8gb is NOT compatible with the NUC and will result in a number of errors including, but not limited to random BSOD, OS installation problems, and crashing.

Other Thoughts: I would recommend the NUC, but no the Newegg bundle.

Pros: Really nice balance of power efficiency, small space, decent CPU. The M.2 SSD slot is awesome, and Newegg bundled it with free RAM.

Cons: I've spent (wasted?) a rare free day trying to get this thing to even complete an installation of Ubuntu (tried 15.10 and a beta of 16.04). There are random crashes and kernel panics during installation or shortly thereafter, even with X graphics stopped. Finally I have tracked down complaints of a 'WHEA' issue (named after the BSOD Windows users see). Seems to be something to do with power management and overheating, perhaps. Lots of people on the Intel forums have had their units replaced, swapped in the same RAM / M.2. SSD / keyboard dongles and found the problem has gone away. Two BIOS updates later (the 'latest' one is pointing at v036 but the forums recommend v039 which is actually the latest) and I'm hoping various memory and/or power settings can get the thing working.

I wanted to pay for a known brand to avoid this waste of time. Not sure if Intel can be that brand for me in the future.

Other Thoughts: Don't buy this until the issues are resolved. The bundled RAM from Newegg was Hynix-based which seems to be related to the issues. Otherwise it could be a nice product.

Pros: Small and powerful

Cons: Very picky with memory. The memory supplied with the bundle WILL NOT WORK.
Avexir 8GB 260-Pin DDR4 SO-DIMM DDR4 2133 (PC4 17060) Laptop Memory Model AVD4SZ121331508G-1B
Had to buy Kingston memory.

Other Thoughts: After about 5 hours of trying to install an operating system, I was going to rma the whole bundle. I did some research and found Kingston Technology HyperX Impact 16GB Kit (2 x 8GB) 2400MHz DDR4 CL14 SODIMM Laptop Memory HX424S14IBK2/16 was compatible. Installed and it worked perfectly. Installed windows. Runs very quickly and quietly.