From my experience with baritones (I have a 6-string baritone tunned to B), they give a meatier sound.
This is generally due to the thicker gauge of string and there being more tension - tighter strings.
I met a man named "Mario Bartone" (bartone - ah, how convinient) at a London guitar show. He played a 9-string bass and talked to me about his theorys on how guitar would become obsolete due to the range of these 9-string basses. He owns a guitar shop and such.
When i was talking to him about string gauges he gave me one of the most valuable pieces of advice i've heard in a long time. I can't remeber what gauge he ran on his 9th string, but it was in the 1XX's.
Mario told me: Many people tend to downtune their guitars nowadays, or use baritone guitars. Detunning a guitar ruins it completely. The strings turn from being a labour of love and an art of string tension, into flappy cables. All the effort by the string companies to make the particular string ring out is ruined due to down tunning.
I guess right now i'm really ranting because it's very late where i am now and i've got nothing better to do, but the moral of the story is, the tighter the string, the better the sound. The sound differences onstage between the baritone 7 and normal 7 may be very small (because most of the time it's hidden by distortion huh?
) although you will certainly feal a difference.
I guess you'd really just have to try out the guitars. Frankly, i find baritones a bit of a novelty. I'd never play one normally just because it feals like you're playing a bass!