Don't reroll due to some perceived maturity difference because that kind of thing is totally dependent server, time, and who you make friends with. I thought it was funny when I went to play my horde toons for a while (I got two level 67 horde) and some guy was chatting me up about how the alliance are so dumb. Meanwhile, all my mains are alliance.

As far as content goes, it is pretty cool to see and quest in the other areas, but the early game really didn't have much variety outside the "kill 10 bears" and whatnot no matter which side you pick. It's still cool to see the zones and how they link up as horde. But it's going to be a lot of work just to see some things for curiousity. I found that BC content was almost identical for Horde. You got the same hub city, same quest hubs and basically the unique towns are just the same quests just from a different town, like the difference between Scryers and Aldor.