MBP's Steve all the way! Myself and James have one each, total ownership is around 6 years for both now, and no significant problems at all, any minor bugs, have been fixed usually there and then in the Apple shop, Leicester branch is incredible in its service, and attention to detail, only problem we have is we usually end up buying something else on each visit

MBA, cant see the point, unless you need lightweight machine, but with more power/usability than an Ipad...
Apple care well worth it, but why not buy it towards the end of the 12 month guarantee, that gets you an extra year! (someone jump in if this is not doable)
And yes, well worth the extra money, which you'll soon forget about, once you start using...
Thom