My DVD player has been on its way out for some time. Anytime it switched layers, there was the distinct chance of it completely losing its shit and jumping to some random chapter. It would also stop reading the DVD here and there and just freeze.
So I bought a Sony Blu-Ray and Batman: The Dark Knight to test it with.
The sound is even better than I could have imagined (although I now have to fiddle with the levels on all the speakers to even things out again). My TV is old and only supports 1080i, so there's some loss there, but it's still a big improvement over the old system. And DVD's at 480p are amazingly crisp and sharp.
Totally worth it.