What I've been finding out as my ears get better trained is that all monitors in that $300-400 range start sounding crappy the better your hearing gets. Those $300-400 monitors are like training wheels, you'll eventually grow out of them.
Behringer is not competing with Adam. What's funny is I've had people tell me Behringer are competing with the Mackie monitors like the Hr824. I've heard them side by side and the Mackies were much nicer. I've never heard Adam monitors but I'd sure like to. I wouldn't even know where to go to lsiten to high end monitors. My local GC must think Mackie is high end.