Hello BambiBoomZ,
Thank you for the info on the W3690.
As for an M.2 as a bootable drive, you are correct that unless you have a UEFI motherboard, you won't be able to boot from most M.2 drives.
The thing about the Samsung 950 is that it has two BIOS' (a legacy BIOS and a UEFI BIOS), which is what it makes bootable (compared to other M.2's which don't have a legacy BIOS).
Nelson