It performs great, from what I can see! With the OS on a SSD, everything feels snappy, blazing fast. I haven't done much really CPU-heavy work until now, but if I decide to video edit or stream in the future, this CPU should be up to the task for sure. For the GPU, I only tried out Worlds of Tanks, ~105 fps on Ultra, HD textures, buttery smooth. I will add some additional benchmarks/fps when I have the time to do so.
Take your time and have fun building, it's the best part! I haven't even really had time to use this rig, which is an odd feeling after everything I put into it. But that will get better soon ;)
Of course you could replace it. Just bought the M.2 because it was cheaper than a Sata at the time.
I DID enable it after I took the picture, and forgot to take another one with the new speed. It's running at the correct speed right now.
Thanks! I also found a lot of builds that looked similar to mine, guess these parts are popular for a reason.