unlike T Bird, my experience with Behringer power amps has been fantastic. I have been using an EP1500 in my bass rig since they came out (on my second one, since first one was stolen). It has always been run in bridge mode into either a single 15" cab or a combo of 2x10 + 15. It has never failed.
In my bands PA system we have 2 EP2500's (both were bought as B-stock) and 2 EP4000's that were purchased new.
The EP2500's were our sub amps for FOH and have never failed. The EP4000's have replaced the EP2500 for the subs and the EP2500's have been moved to the monitors. And I'll say this, the EP2500s are really overkill for our monitors, but they work every show and have been completely reliable. We expect the same out of the EP4000's.
Other amps that we have discontinued using due to problems are a Crown CE2000 (would thermal and shut down way to easily, and this hase been my experience with every Crown CE series amp I have worked with) a Peavey CS800 that was retired due to a problem with its input jacks failing and a Carvin DCM series amp (forget the model) that would randomly shut down. FWIW, most other Carvin DCM series amps I have used have not had this problem. All these amps were on monitor duty and were not worked near as hard as the FOH amps.
The biggest problem I have with the Behrigner EP4000 amps is that they are heavy! And I don't like lifting heavy things...lol