I've used some of their older pro sound stuff, but that model is really recent. I'm not sure you're going to find many experiences with them yet.
The older Behringer stuff I have used. It's all an obvious knock off of other designs, their amps are QSC RMX knockoffs, their monitors are Genelec knockoffs, their channel mixers are Mackie knockoffs (and I don't even think they try to hide that, they named theirs the Xenyx and Mackie's is the Onyx), and so on. Their crossovers are dbX knockoffs, but they work fine and cost a fraction of the dbX stuff.
It's affordable stuff though, that's really the purpose of it.
As far as what the unit is used for, a lot of times those active 12s are used as booth monitors. Though, Behringer stuff isn't used in clubs. I'm sure some people will use them for little portable party setups. That's pretty much their market.