Hi Hbrandt, I have to reply as my middle name is Brandt and I own and sell the Innersound ESL amps (and product line).
The ESL amp is specifically designed to drive electrostatics and puts out 600 watts per channel into 4 ohms. A local dealer has the Marsh amp and it doesn't drive the Soundlabs very well at all but the ESL amp (they also carry them) has no problem gettting the most from the Soundlabs, which are as hard to drive as anything out there. As for the sound quality, I believe they really compare to the very best and you might want to go to www.innersound.net to read what 3'rd party reviews of the amp have to say. If I can answer anything else for you or help you acquire one, please let me know.
The ESL amp is specifically designed to drive electrostatics and puts out 600 watts per channel into 4 ohms. A local dealer has the Marsh amp and it doesn't drive the Soundlabs very well at all but the ESL amp (they also carry them) has no problem gettting the most from the Soundlabs, which are as hard to drive as anything out there. As for the sound quality, I believe they really compare to the very best and you might want to go to www.innersound.net to read what 3'rd party reviews of the amp have to say. If I can answer anything else for you or help you acquire one, please let me know.