I've always used Samsung SSDs and I'm curious as to the difference between the EVO and the Pro (I know a little about the 2 bits versus 3 bits per cell), but from a practical (user's) standpoint is there a noticeable difference? I have a machine used for audio production (Pro Tools) and it's critical to have project files on a separate (preferably internal) SSD. My 256 GB 850 Pro is getting to be too small (lots of projects). Is the much higher price tag for the 860 Pro worth it?