Well I would first like to say hello to everyone, I wanted to share my new to be computer build. I enjoy gaming and have been looking into unreal editor 4. My current computer is a Antec gaming 900 case, Antec 850 TPQ power supply, EVGA 780 sli FTW mobo, 8 gigs DDR 2 800 ram(not sure about latency), intel core 2 duo EX850 3.0 @ 3.6 OC.. FSB @ 1600... I just bought R7 1700, gskill trident Z 3200 14 latency ram, and ASRock x370 taichi mobo should be in monday. I currently have an old 40 gig ssd drive and 2 7200 250 Gig HDD. Ooh yah and I replaced my gtx280 with a gtx 1070 ... My question is should I bother with the NVME drive... maybe samsung 960 256? or should I just put my funds into a large Sata SSD, maybe raid two? I hear those NVME get really hot... perhaps i could drop a heat shield on it, if that will help?
Do you want to spend more for the extra speed of a NVME drive?
That is the only real question here. You pay more, you get more speed.
As far as value goes, a SATA III SSD is still very fast. The extra cost for the 960 has to be weighed in by you. For gaming, definitely a waste of money for the extra speed. Capacity will probably be more beneficial.
A larger decent SATA SSD should be your first priority I think, like an 850 Evo perhaps. The bigger the better they perform.
While NVME drives are much faster in syntetic tests they typically don't lead to faster boot times or quicker loading of games than any decent SSD. I did get a 250 GB 960 Evo for my Ryzen since I already had plenty of SSD storage and the old system drive were to remain with that build. Other than perhaps a bit quicker installation of larger patches and stuff I can only confirm the results from real world tests in reviews, that they're not noticeably faster overall.
Heat isn't generally a problem though as it only shows up in long running tests. Typical use doesn't tax the drives that hard. The x370 Taichi has an okay placement of the main M.2 slot too which can help. Some boards put it right under the graphics card which is much less ideal.
Hello and welcome to the community. 
Hey, welcome to the community.
My answer to your question is no. NVME for standard use is absolutely not worth it. You can easily get an M.2 drive, but NVME, with it's current pricing - no... SATA is doing fine. Instead of 20 seconds you will boot in 35 with the sata drive...
NVME is something, that isn't really needed by 99,9% of all users.
A fast SSD would be the better balanced option for your build, as well as better performance for the money.
When it comes to thermal considerations, the only potentially troubling issue is that some mobo's mount the NVMe drive beneath the GPU, which is probably the worst possible choice. My GPU is water cooled, so my NVMe drive runs much cooler than I expected. As a matter of fact, the temperature differences between my NVMe drive and my SSDs, is insignificant.
It depends on what you're doing, but I would lean toward a lager capacity SSD over a faster one in most situations. The latest SATA SSD's are pretty fast anyway.
Does your PC take 35 seconds to boot to the OS, from a powered down state? My system cold boots in under 20, easily... 15-17 seconds. My other PC with a HDD for the main drive takes 35 (roughly) seconds.
Note: I am using an old Corsair Force 3 SSD (MLC, Sandforce). More modern flash drives are much faster now.
ADATA SP900 64GB... It's old, it's small, it's budget... From button press with all hardware checks and everything, W7 ultimate 64bit - about 27sec...
My point was, that there will be a small difference between sata and nvme boot time, that is extremely insignificant compared to the price difference...
I own both an NVMe SSD and a SATA SSD and I have to say that in probably ~90% of situations the extra speed of NVMe is completely unnoticeable. The OS loads slightly faster and some games have slightly shorter loading screens, but for the most part the difference between the two in normal tasks is negligible.
I say get a larger SATA SSD before an NVMe drive any day of the week.
Get an Intel 600p, NVME drive with the price near those SATA, so you can easily go with a large and fast single drive. Not as fast as the 960 EVO but still I find my 600p snappier and faster than my 850 EVO.
Take this into consideration here: You pay a butt load of money for a PCIe SSD and waste the slot, you only have 128 GB of space because thats the most affordable, and if the drive dies well fuck you're out 800 bucks on a gimmick.
Meanwhile, I have a 64 gig low end SSD out of a samsung laptop from 2010, probably out of a chromebook, and booting xubuntu, antergos, BSD, and windows 7, around 2-5 seconds.
/shrug I mean you could go the extra 9 and have that stupid speed, but what are you really going to use it for? You could max out your ram and have a ram disk for stupid fast file retrieval.
Well thanks for the welcomes and opinions. My recent thoughts were using the NVME for unreal editor 4 and possibly music editing/recording... boot from the 40 gig SSD I currently have, and get another terabyte or 2, 512 Gig SSD, for games and puttering around. I am going to keep the 2 sata 7200 mechanical drives just for back up, cause they are still useable, and the mobo has 10 SSD slots.
Maybe at a later date get another SSD or two for a Slackware dual boot.
Well thanks again for all the information.
I don't think an NVME drive for just the OS and general purpose use it's worth. A SATA SSD is plenty fast and programs usually take time to load because the way they're programmed more than due to drive speed. A reliable 850 Evo or 850 Pro is my suggestion (I have an 840 and and 850 Evo and they've been doing really well, that's why I'm reccommending Samsung).
Heat shields are a market gimmik and can even slow down the drive due to controller overheating. You'll be better off buying those little heatsinks for Raspberry Pis and slap some of those on the drive with some thermal paste.