Oh he most definitely matures a lot throughout the series. GoF!Ron can GTFO as far as I'm concerned, but by the end of book seven I actually like him quite a bit. AND, unlike Xander, Ron tries to redeem himself and/or apologize for his actions. The text acknowledges a lot of Ron's faults, whereas on Buffy we're constantly told that Xander is such a nice guy without them ever really acknowledging the blatant misogyny or condescending attitude.