Thomas G,
For me, the original 200MB (RCB), 400RB, and 800RB were Gallien-Krueger's finest achievements, but that's just my opinion. Jimmy is correct, that the Backline amps sound infinitely better through other cabinets. I was told by a very reliable source that there were some problems with the earlier 700RB and 1,000RB amps. Gallien-Krueger replaced the all units that had the problems, but my source, a GK dealer stopped, carrying the line because he had to send a number of units back to GK for replacements. GK replaced all the heads. I had three GK micro bass amps a 200MB series I, 200MB series II, and a MBE. None of them every had any problems. So regardless where the amp comes from, problems pop up from time to time. The Backline amps weren't totally new designs, like the MB500, MBFusion, MB200, and MB800 heads are. Personally, IMHO even with your own plant in mainland China, running an entire new line of amps from across the ocean has some built in difficulties.
Ric