I always though Scott Carpenter was one of the most interesting of the Mercury Seven. He was a sort of an outsider from the other six; he'd flown P2V patrol planes in Korea rather than jet fighters and was a bit of a "free spirit," at least as far as 1950s-1960s military officers went. But he didn't care about fitting in, he was happy how he was. He got in trouble over MA-7 and that was that; my personal take on it is he didn't do anything really wrong but had some issues that maybe another pilot would have handled better. Unfortunately for him he was dealing a very rigid, zero-tolerance management. Which is understandable, the stakes were very high and the pressures were unimaginable. If he had been in a later astronaut group, he might well have flown again.
A brilliant and fascinating guy and a classy gentleman, I'm really sorry to see him go.