How would Claire's abilities allow her to learn to become an Olympic level gymnist in an afternoon? That sounds like Micah's cousin from Season Two who can mimic anything she sees...
The person who said that was using hyperbole, no doubt, but Claire
should be able to do some really amazing things. The entire reason most people can't lift a car in normal circumstances is because of the pain, muscles ripping, and so on and so forth. Claire doesn't have to worry about that sort of thing. At all.
The problem, however, is that Claire shouldn't be able to actually improve her physical condition. Any weight training she does will just be "healed" back to normal. At best, she
might be able to work on her muscle memory, allowing her to practice things like gymnastics and acrobatics, but it wouldn't go too much faster for her than it would anyone else. She'd simply be able to skip all the safety measures most people take when learning and training.
I also always liked having Monica on the show. With her, Peter, and Hiro's now-dead flame (which, incidently, is why Sylar seems to be so smart now) was a great trio of powers that were similar but vastly different. One could do any physical action that any normal person could do, one could do all the extraordinary things that people with abilities could do, and one could do anything someone could learn to do by reading and studying. I just thought it was a really interesting take on the standard comic book power mimicry.