I have a pair of older Martin Logan Aerius i speakers driven by a yet older McIntosh MC2200 amplifier. Certainly not quite as refined as the ARs but I feel the speakers suck every ounce of (200wpc) power from the amp with the volume at moderately high levels. I think the 75wpc amp may be a little strained depending on your room size and listening habits. But amp aside, I personally find electrostatics sound an acquired taste. While they sound detailed and create a decent size soundstage, they have an extremely narrow listening sweet spot that can be annoying. Definitely try them first before you commit. With a solid foundation like the ARs, you have a lot of speaker options to choose from. I've heard your amp/preamp combo with a pair of larger and older stand mounted Aerials - not sure which model, maybe LR5, in a moderately sized room, and I was really (really) impressed. Definitely sweeter sounding than my set up.