I've got a Samsung S2 - I think it's very good indeed. Not just as a smartphone, but also the quality of the phone reception is better than any other phone I've ever tried.
As to the iPhone/Android debate there is good and bad on both sides - I happen to dislike the 'nanny state' approach of Apple and prefer the less regulated (but occasionally more flaky) google market.
The main current issue with the iPhone5 is Apple's daft decision to replace google maps with their own (useless) product - check this out if maps and satnav are important to you.