I was faced with the same decision (R3/R5). I went with the 2012 R3 Team, primarily because I was able to get it a month sooner than the R5. Having had the R3 (which I like, a lot, btw), I kinda wished I had been patient, and waited for the R5. R3 is a great, smooth ride, but sometimes I find that it's a bit too forgiving. I kinda wish I had a little more "feedback" from the road the R5 would've given.
Just waiting for the new frames to come out, hopefully with internal cables. Will pick up an R5 (assuming it's called the R5) when released.