I actually had a trip done to the local specialist camera shop today, looked at the 24-105mm on a 550D, looked at the 15-85mm on the same, played around with the 7D and the 5D MkII, what a flipping big and heavy handful the 5D is !!!
I just can't see me walking around with a big FF camera, but may look at one again at some point, but for now, I'm more likely to stick with a crop next time I upgrade.
The 7D and the 5DII are almost exactly the same size and weight (the 7D is very
slightly smaller, but also very slightly heavier). The 60D is only a little smaller than the 7D. But compared to a Rebel, any xxD or xD body will seem big and heavy. Personally, I like the weight and I add to it with battery grips on both 7D and 5DII - that extra weight helps counterbalance the lenses I use (although when I had an 85mm f/1.8, that felt a little weird on the gripped 7D).