get the behringer, although I hear good things about biemma I have no first had experience with them.
The behringer can do 260Watts into 8ohms(I think?) and will drive a 2ohm load if needed, I can't see the biemma doing that (although you never know). Also I hear that the behringers are re-cased QSC RMX series amps.
http://www.qscaudio.com/products/amps/rmx/rmx.htm I believe the RMX 1450 is the same as the EP1500.
hope this helps.
dr f