I just got a BD-UP5000 to replace my HD-A2 and BD-P1200 players and I'm glad I did.
The sound output over optical to my Sony receiver is much better than the A2 was. Bass is fuller and highs are crisper. I have the 5000 set to bitstream (Audiophile)
I also noticed that the video on HD DVDs is less "noisy/grainy" set at the same 1080i resolution. My experience is that this Combo unit is better in every way than the other two players.
All that being said, I do have one concern with the 5000 however. It seems to get extremely HOT on the underside of the unit, especially on the right side. After the player has been playing for a while, if I place my hand on the bottom sheet metal, it feels pretty darn hot for an electronic device! I checked the fan on the back and it's working fine and there's plenty of air space all around the unit. It is sitting on its own shelf by itself.
Is this normal? I know that high heat can shorten the life of electronics and it seems that maybe Samsung uses the bottom sheet metal of the chassis as a heatsink for a large power hungry chip.
Can anyone verify that this is the case? Is this normal?