We bought our bedroom set from Bob's. I LOVE the mattress (Bob-o-pedic) but the actual furniture isn't the best quality. It looks great, but when you use it you can tell it is low quality. For example, we pushed the dresser closer to the wall and broke the leg off!! We called and they replaced it the next day, but that is pretty crazy!
For a kids room...definitely go with Bob's. Chances are, the kids furniture will either get ruined from typical kid wear and tear, or their tastes will change in a few years anyway. I would never buy expensive furniture for the kiddos.