[citation][nom]eddieroolz[/nom]Didn't watch video, but I hope the Android tradition of laggy UI is resolved. That's one of the many things that's kept me away from even considering one.[/citation]
I don't know where you got the idea that Android GUI's are laggy. I have used different HTC devices in the last years. It was slow with some low-cost underpowered phones a year or two ago, but since the Nexus or HTC desire, everything runs at least very correctly and even perfectly smooth when using non-sense Roms or when using a fixed image rather than animated wallpaper.
From my experience, iPhones give sometimes the feeling of being smoother because Apple implemented lots of fancy animations that keep you busy while you wait (screen rotate animation, zoom & fade when switching applications...) but eventually, you'll wait after the applications to respond just like with any other phone.