Basic AVP made me enjoy AVPR more because AVPR was...well...as brutal as you'd expect an AVP movie to be. AVP unrated felt equal to basic AVPR. and AVPR: Unrated just made a good thing better. I've no desire to watch the theatrical cuts of either again.
And the little things in AVP Unrated aren't much, but the new human interest stuff like the extra dialogue between verheiden and dude kinda slowed things down and added some substance where there wasn't really any before. And yeah, when somebody gets slashed open, it kinda helps the believability to have some blood come out.
I enjoy both movies quite a bit now, and I don't think that would've been the case without the unrated cuts.