I used to have the PAL DVD and now have the R1 Immortal Edition and I don't think either are great for PQ or sound. They will be better than VHS though so if that's the worry, buy with confidence.
Even with DTS on the R1 immortal edition, I found the sound was thin and lifeless, and a quick comparison with the supplied CD shows how much better the songs can sound.
I hope the BD rectifies this.