I like the Racial Paragon classes. It's a cool way to flesh out a character who gains a level but isn't sure what direction to go with classes, prestige classes, etc. The only thing I really don't like about them is more fluff based than anything else, the idea being that these characters are somehow 'better Humans' or 'better Half Orcs' because of taking the class. I see it more as investing time and effort in doing non-class specific things that your race tends to do.
The +2 to a stat sure is nice. It's like enhancing the racial mods you get at first level. I don't find them particularly gross because the Racial Paragon classes themselves don't offer that much wow, and working your way up to 3rd in a Paragon class isn't easy. The +2 mod is like the pot of gold at the end of the rainbow so to speak.