I'm very impressed with this nifty little NUC.  Just got it today along with 2x8GB of ram for testing.  I got the short version that only has room for a NVMe card.  Testing DragonFlyBSD on it and everything works, which means that it will also work well with Linux and FreeBSD (though I don't know about video accel in FreeBSD).  And Windows too, obviously, but who cares about Windows :-).  Here's the official CPU identification:CPU: Intel(R) Core(TM) i5-7260U CPU @ 2.20GHz (2208.06-MHz K8-class CPU)This cpu is a 2-core/4-thread Kabylake 'U' mobile cpu.  I verified that it Turbo's to 3.4 GHz on both cores (all four threads), and will stay there when I load them all down.  Performance is roughly equivalent to an older Haswell i3-4130 desktop system (which was a 2-core/4-thread @ 3.4 GHz), though of course with NVMe based storage the filesystem is a hundred times more responsive than a hard drive.I tested: network booting with PXE, usb booting (EFI), and NVMe booting (also EFI).  The ethernet works (if_em or if_emx in BSD-land probes the Intel I219-V4).  The Wifi works (if_iwm and iwm8265fw firmware).  USB works.  Sound works, X works fine on a 4K screen.  I didn't have a usb-c cable to test a second screen (got one, see note at end).  AHCI not tested but looks standard so would certainly work too.  Primary screen is via HDMI.  xrandr output:DP1 connected 3840x2160+0+0 (normal left inverted right x axis y axis) 610mm x 350mm  3840x2160  60.00*+  30.00  25.00  24.00  29.97  23.98I am very impressed with the performance.  It has no trouble running X on a 4K display, no trouble running chrome, no trouble running YouTube full-screen on the 4K display.  Very responsive to the UI.  I couldn't test a 2160P stream due to network bandwidth limitations but 1440P on a 4K screen looks wonderful.Power consumption is equally impressive.  Here are the numbers at the plug with a kill-o-watt, and keep in mind this is WITH a NVMe card plugged in and Wifi operational:14W - BIOS11W - During kernel boot10.5W - Idle, VGA console (C1)10.3W - idle, frequency management only (C1)10.0W - idle, C-state management (C7)12.0W - typical downloading over the ethernet10.0W - chrome idle20.0W - chrome loading YouTube page10.0W - chrome idle w/YouTube page loaded13.0W - Video playing, embedded (1/4 screen)15-17W - Video playing, full screen (4K screen, 1080P stream)11.3W - Video paused, full screen13.5W - YouTube music (1/4 screen, very little video action), over Wifi23.2W - YouTube music + 32-process 8KB block size random read test from NVMe storage.  All cpus fully loaded.  1.4 GBytes/sec read rate.Temperature tests:48-50C - Typical idle54C - youTube music playing, low load62-70C - fully loaded test (as described above)Note that both cores (all four threads) stay at 3.4 GHz turbo during the fully loaded test.  Temperature increased rapidly to 62C, then fan came on (which I can't really hear), and temperature slowly increased after that to 70C and then stabilized there.  Frequency remained fully Turbo'd.  This fully loaded test is not using the FP unit heavily... its mostly integer, plus whatever chrome is using (probably mostly GPU video accel and not cpu FP).  So its not the absolute maximum load I can put on the system, but its already well over what most people would run it at even doing lots of stuff.  Unloading the cpu but leaving YouTube up playing music, temperature instantly dropped to 65C and then headed down to 56C from there.I have to say, I am very impressed with this little guy.  Being able to get Haswell i3 desktop performance from a few years ago packed into such a small form factor is amazing.  I've tested many NUC's and BRIX's (as well as many other systems), and this is really the first NUC/BRIX form factor that I would be happy to use as a workstation.  Mind you, I have servers to do major compile jobs on and such... I'm talking mainly for X windows driving two 4K displays with lots of xterms and chrome windows up.  Video, music, etc.  Not heavy processing.Addendum: I got a USB-C to HDMI cable and after a bit of scraping I got it working.  The second display ran at 4K@30hz so now I have a USB-C to DP1.2 cable ordered to see if I can get them both running at 60hz.  I'm still going to give the NUC 5 starts, but I will note that the NUC's USB-C port is deeper than spec, so the cable wouldn't plug in solidly or connect at first.  After a bit of shaving of the cable housing I was able to push it in deep enough to connect.  Insofar as I can tell, this is a problem with the NUC usb-c port being a bit too deep inside the case.  I also noticed that the motherboard in the NUC wasn't properly seated, and corrected that, but the usb-c port issue looks unfixable (other than by shaving the housing of the cable I plugged into it).Addendum2: Sound output on the stereo plug has serious hum.  Tried everything... grounded speakers, ungrounded speakers, even found a three prong power supply for the NUC.  So I gave up on using the stereo output plug.  The HDMI sound output works fine, no issues at all, so I used that.  Not going to dock Intel a star for messing up the stereo output since an alternative is available.Addendum3: Still can't test with a DP1.2 cable (snafu trying to order it on Amazon, package was returned for reasons unknown), but I have two 4K monitors running at 30Hz no problem (which is fine for a workstation).  Have been using this NUC as my X workstation for a while now and it works great.  I'll note here that if you are having problems running 4K@60Hz, its probably that your cable isn't rated for it.  In BSD/Linux you can just use xrandr to set the vertical refresh to 30hz to work with older cables.I would also like to note very specifically here that I am using a *real* NVMe SSD and not the Intel Optane junk.  *NOBODY* should ever buy Intel's Optane junk.  It's a rip-off and it makes zero sense to waste the NVMe slot on it.  Buy a real NVMe SSD card, like a Samsung 950/951/960 series NVMe card (e.g. like a 250GB+), and install the system directly onto it.  Remember that this NUC is bare-bones.  So you need to also purchase the ram (DDR4 laptop memory, I recommend 8GBx2) and the SSD (I recommend a Samsung NVMe SSD of some sort).  If you need tons and tons of storage, get the taller version of the NUC and install a secondary SATA SSD or HDD drive in addition to the NVMe system drive.  I would still recommend a SSD as the secondary SATA drive but with a little work you could probably fit one of those fat 4TB 2.5" Seagate HDDs in the tall NUC (I have the short NUC so I can't test whether a fat 2.5" Seagate would actually fit in the tall NUC form factor).As I said, I am still going to give the NUC 5 stars even with these deficiencies.  Buyers are warned :-).  Get a USB-C to DP1.2 ('Club' brand adapters are what Intel seems to recommend), have an xacto knife or box cutter handy just in case you have to shave the housing to get it to plug in solidly (remember, you can also shave the NUC case housing instead, if you don't want to shave the cable), and connect your audio through the HDMI port rather than the stereo plug.-Matt