I'm assuming the UK Region 2 version is the way to go, because of many more extras, but does anyone prefers the US version (or one from some other region)?

I don't think it's even "many more" extras. From what I understood it's just the two commentaries that got cut(there are four on the UK dvd, the ones that didn't make it were Penelope Wilton and Bill Nighy on one, several Zombie Extras on another - the creator and main cast commentaries remain). Everything else looks to be the same as the region 2 UK dvd I have. It's up to you if it's worth trading two commentaries(which are good but nothing special) for a NTSC picture(I don't really notice any speedup or anything on my machine watching the PAL disc, but if you're very particular you might).

The American version bumps up the background music a bit. Personally, annoying. Mileage may vary.