Yeah, I agree with Yikes. It sounded good.
Unscientific testing, but I put my hand on the B-52 while listening and it wasn't hot.
As for cost, I don't see how it's inconsistent. Dynamight or GS-X are the cheapies of this class. Maxed out SDS XLR is the expensive one. The rest - B-52, balanced Maestro, balanced Max - just fall somewhere in the middle.
Actually, now that I think about it, the balanced Grado amp is the cheapest.
Best,
-Jason