What does the R2 Blade Runner feature?
The R1 Blade Runner is Ridley Scott's crap director's cut with Deckard's commentary deleted, and with extra scenes folded in to make the viewer believe that Deckard was a replicant, because that is what Ridley Scott thought despite the fact that Philip K. Dick himself has said that he never intended for Deckard to be a replicant. .
Aside from that, the issue of Deckard's narration...there are some of us that LIKED that part. IMHO, it gave the movie an old world detective novel feeling that matched very well with the retro futuristic setting, and especially Deckard's character.
I think that the R2 version has the commentary and is minus the scenes, but I'm not sure.