As a current owner of McIntosh MX160 and MC8207 and former owner of a pair MC1.25kw mono blocks the answer for me is go with the Luxman. Two years ago I decided to "see what else was out there" and demoed several amps from various manufacturer's. I demoed Luxman, Audio Research, Boulder and a few others. Without a doubt the Luxman was significantly more musical and provided much more depth and detail than the McIntosh. You could hear music on the Luxman, in terms of detail, that you do not hear with the McIntosh. Research Ohms law and it will help provide more guidance about how the Luxman operates versus the McIntosh. Because the Luxman goes lower in Ohms, especially with electrostats, you will be amazed at your improved soundstage and overall tonality. Another thing because of how the Luxman is built you don't need as much watts per channel to drive the speakers. At the time I had Martin Logan ESL15 electrostats and the Luxman combo "blew away" my Mac/Martin Logan combo in every way. So, my vote is for the Luxman and don't look back.
Let us know what you decide to do.