Personally I find the Intel m.2 you mention far too slow. There are basic SSDs which are nearly as fast.

vengeancewithin
I know they're relatively new but was curious if anyone has tried the Intel 600p M.2 drives in a X99 Classified? Speeds are not nearly as fast as the Samsung 950 Pro but it's also not nearly as much monies. Would the M.2 in the X99 Classified decrease that speed further since it's PCIe 2.0 x4? 
 
edit: Link to item in question 

http://www.newegg.com/Pro...nalSSDs-_-20167412-S0H

The PCIe 2.0 x4 still holds the advantage over SATA based drives. Just keep in mind that the signal is shared with the PE5 slot on the X99 Classified. You will have to enable M.2 in the BIOS before you are able to use the drive.

Let's be honest. Writes matter only if you do a lot of write oriented work. On Gen.2 M.2 reads won't be massively affected. About 150-200MB/s less than nominal speed (not including possible overhead from OS as nothing ever works at 100% peak efficiency - well perhaps except black holes, but that's something different entirely :D). Granted if you reading 2TB database, every little bit helps, but I doubt Vengencewithin getting this for DB.
 
Most folks look at R/W ratings and always want much more than needed. If you have to deal with tons of data like VMs, databases, RAWs, editing video, then yes writes are important - I can see the difference between 750 and normal AHCI when I try to load/save to/ directories with 80 or 100k files inside (normal SSD chocking itself to death). If somebody is only getting 600p for games, writes are not important whatsoever. 
 
IMHO much cheaper option (and simpler) for games is 850 EVO with RAPID enabled. Everything will fly and it'll leave NVMe in the dust.

Thanks for the replies. My use would be primarily for READ speeds. I have an 850 EVO for my games and was going to use this for my OS. Was mostly just curious if anyone has tried it in a Classified and what kinda speeds they got. Thanks again.