Bow Wow
more successful at rap because he actually released more than 2 albums and fed off the hype surrounding his name when he was younger, but will never be respected as an artist because it's BEEN known that as a "child rapper" his lyrics werre written for him by others...he'll probably never sell outside his original market because his image and lyrical level hasn't caught up to his real age and maturity level...if he wants to be around for a while, he'll have to step it up a lot

Lil' Romeo
has his own TV show on Disney, with sindication on ABC, ABC Family and the Disney channel itself, he'll probably end up making more money than Bow Wow in the long run and he will probably end up rapping again once he gets older and decides to release albums, or play basketball, cuz I've heard the kid is quite sikk with the rock...if not, his father's rich LMAO

but to answer the question, there's always gonna be beef in rap because it's a lot more competative, there's not as much room for rappers because we generally don't distinguish things to different categories so that everyone can be on top at the same time...as opposed to rock music where there's different genres within it, that have completely different sounds from the other...when everyone sounds alike, there's always more competition for who's the best out of that particular sound...if rap was more diversified htere'd be less beef
but that's just MY little opinion