I’ve owned the 11A’s for a bit over two years and am very pleased with them. I drive them with a Mcintosh MC452. At least one other A’gon member had this same combination and found it not to his taste. However, I spent months shopping for a new amp after getting the speakers and this pairing seemed to offer the best combination of resolution and smoothness of the amps I was able to evaluate.
I am using the ML’s in a 13 1/2’ x 19 1/2’ room and I believe they are a good fit, but if your room is larger and your budget allows, you may want to compare against the 13A.
It has been too long since I’ve heard the Summits, much less the Quests or Re-Quests, to offer any detailed comparisons to the current line. I will say that, while Martin Logan may have worked on refining their stat panels over the years, some of the biggest changes have occurred in the implementation of the bass modules in their hybrids. I was skeptical of all the digital voo-doo going on, but it sure seems to work. With adjustments available for overall bass level, mid bass boost or cut, and Anthem Room Correction on the Masterpiece lineup, they offer a variety of tools to allow the speakers bass response to be tailored to the room and the listener’s taste.