The Atlanta concert was awesome. And R.E.M. is my favorite, so I went crazy when Chris announced that Michael Stipe was the Atlanta surprise this year. Michael and Chris performing "Nightswimming" was great.
I'm going to see them again in either Orlando and/or Tampa. I suggest you do the same if you really want to see them. It'll take you about 6-7 hours to get there depending, etc. I'm trying to do the presale for Orlando but really want to go to the Tampa show: I have the feeling that Coldplay will make a special effort to make this show great since it's a make-up for the one they missed this year; it's also an amphitheatre (outdoor, I believe) venue, so all seats will be great and the sound will be great. There are even general admission tickets for Tampa if you like that kind of thing. Good luck. I hope you get to see them. Their Atlanta concert this year was the best I've been to.