Yes. To my ears, the AVA 550exr is a wonderful match with the Maggie 1.6s. I've had the 550 for about 8 months, and have no desire to keep looking for something else to drive the Maggies. As I'm sure you already know, the Maggies really come alive with both high current and a lot of high-quality watts, and the 550 certainly provides plenty of what the 1.6s require. If you haven't already done so, I'd suggest reading some of the in-depth reviews of the 550 in this circle.
The 550 is very fast, dynamic, detailed, clean and smooth; if a recording has powerful bass, the 550 and the 1.6s will reproduce it. I've never heard better reproduction of a well-recorded acoustic bass than with the 550 and 1.6s.
I have my 550 paired with a VTL 2.5 preamp, and though folks say the AVA power amps have a great synergy with the AVA preamps, and I'm sure they do, my 550 and the VTL get along just fine.
