I've owned a few 200-300+wpc @8ohm amps, yet couldn't find one that did the muscle-amp thing better then a PS Audio HCA-2. It had deeper, faster and more articulate bass then any of the monster amps, played just as loud, yet was vastly more refined all around. It's only billed at 150wpc but I have yet to find any amp under 400wpc that I'd repalce it with (The JC-1's and Musician III only come to mind) The HCA-2 can be found for around $1200 used, and older Spectron amps are getting down there too, which are also a killer hi-hp amp with overall good sonics. If you have big electrostats that are under 87dB effiencint the Spectron will easily be the better choice, otherwise it's a personal preference matter, me thinks.