Something else to consider for anyone looking to upgrade to m.2 or SATA SSDs - m.2 drives are even faster than the already fast SATA SSDs. On my system (ymmv), my m.2 drive is 4 times faster than a fast SATA SSD. I did read and write tests with big files and the SATA SSD is a slow-poke compared to the m.2.
I think the m.2 drives can be on busses that interfere with other devices, though, and anyone considering one should double check and double check even mobo compatibility, but my next build won’t even have SATA SSDs now. Just spinners for backup duty.