I have not researched Blu-rays enough before buying my first one. You can't even play one on Windows by default, and VLC and MPC both require following arcane instructions from user forums to make it work. That's the last time I bother. DVDs were the superior format.
@Gargron Yup, it's terrible. With DVDs, all you needed was libcss, but for BluRays you end up downloading databases full of keys just to realize your specific BD isn't in it...