First of all, what has Rivers ever done in the offseason that could be considered a personal foible? The only reason why he has a bad reputation in some people's eyes is because of two incidents; the Christmas game against the Broncos a few years back when he and Jay Cutler were yelling at each other; which by the way Cutler instigated when he grabbed his groin and cussed at the Chargers sideline. Cutler has shown himself to be a low class loser of a QB who blames everyone else but himself for his poor play. Here's a clip of that incident. The camera only caught the part with Rivers yelling at Cutler; it didn't catch the part before that where he was holding his groin and yelling at the Chargers sideline. Anyone watching the clip though should automatically wonder why Cutler is the only Bronco still standing out on the field when the rest of his offense already went to the sideline; clearly he was the instigator:
YouTube - Philip Rivers Trash Talks Jay Cutler
The other incident was the playoff game against the Colts in the 2nd round when Rivers was caught on camera jawing at some fans on the sideline. He never cussed at them; he's just got the kind of personality where he likes to talk trash to anyone and everyone including the fans who instigate him. He hasn't jawed at the fans since that incident though so I figure that the coach must have told him to cut that out. But, he still talks trash to players on the field and a lot of defensive players respect that. Joey Porter said that of all the QBs in the league, he likes playing against Rivers the most because whenever he talks trash to Rivers, he gets it right back whereas Manning and Brady just ignore him.
I don't know about you but I like my QB to have a fiery personality; some people prefer the quiet Tom Brady type but clearly the fiery personality works for Rivers and is not affecting his level of play. A QB can't elevate his game to the level of Brady just by being quiet; both Brady and Rivers are elite QBs regardless of their personality. Off the field Rivers is a devote Catholic and a family man; he has like 5 kids last time I checked and he never goes out to party with the rest of the team; playing basketball with Antonio Gates or golf with some of the players is all he does outside of football, family, and faith. He drives a ford pickup truck as his only vehicle so that should let you know what kind of person he is, but I should let him tell you in his own words:
YouTube - Philip Rivers: Faith, family, football... in that order.