Your reference to hard to drive Infinity Speakers brings back memories of my first "high end" purchase. In the early 70's I was at a hi-fi store in Palo Alto. They had the Infinity 2000A Electrostatic speakers (4 Ohm) on display playing a Cat Stevens album. To my young and naive ears they sounded spectacular. I don't know what amplifier they were using, but it was probably top quality, better than my Sherwood receiver at 60 watts a channel. I scraped up the money and bought the Infinity's. They sounded great even though my Sherwood was probably struggling to drive them. About a year later I traded them in, the speaker's power cords were quite inconvenient in my small apartment.