Epona222: It works almost seamlessly for me (Phenom II quad core 3.4Ghz, 4Gb RAM, HD 5850) it seems there's always some complaints in most games about transitioning through doors, I'd rather have this barely noticeable delay than loading screens - and really it's one or the other so take your pick, IMO this is the lesser of two evils.
I think it has to do with the fact that you can *see* the new zone through the door, and it looks like something you should be able to more organically transition. If it were a more primitive traditional "dark doorway and a load screen", people probably wouldn't raise an eyebrow.
Of course, then they would be looking at a load screen. I'll take the syrupy doorways.