Quad 2912 vs Martin Logan ESL 11a

I have no experience with the Quads. I do own a pair of the ML 11A’s and love them. They are fast transparent and airy. They deliver awesome highs without being fatiguing. The mids are full and warm and do not get cluttered. The bass is fast and rich.
There is a big difference between the masterpiece series and the rest of the Martin Logan line up. I suggest taking a listen to the 11A’s and see for your self.

@pvmike2 Thanks for that assessment. I have arranged an audition of the 11a this weekend. Looking forward to confirming that the integration of bass with electrostatic panel is not an issue. I will report back shortly.

I'd vote for the Quads. ML's always sound too bright to me and a bit tizzy, and the bass doesn't match the speed of the stats. But of course your own ears have to be the judge!

I would consider room geometry and how much fiddling you want to contend with to set them up properly. I have heard, but not owned, Quads. I currently have M-L Summit X's, having owned the M-L Odyssey's and Magneplanars in the past.  

I'm well satisfied with the bass especially on the newer M-L's that include DSP. With my "older" Summit X's without DSP, the bass integrates well with 95% of the material I play. With Quads, you might end up adding subwoofers to augment the last octave.
The ESL 11a's are very similar in sound to the Summit X's to my ears. I've found with M-L designs that the lower midrange and midbass tends to get richer and fuller as the panels get wider (i.e. ESL 13, 15, and CLX). Of course, the price also goes up.

I think the main thing to consider is that the ML's behave as a line source due to the geometry of the stators. With M-L's, at least in "normal" sized rooms, you will need extensive diffusion treatment on the rear wall behind the speakers to mitigate comb filtering effects that can cause VERY annoying peaks in response in the upper midrange / lower highs. They also like to be a fair distance from the side walls, as well. Upper frequency response is fairly sensitive to toe-in (mine are pointed straight ahead) and rake angle (adjustable with the supplied footers).   They require time and patience to optimize.

I auditioned the ML 11a yesterday. The speakers were not optimized in their placement and the source was a smart phone streaming through Tidal, although with Anthem electronics. Given less than optimal conditions, and no more than 40 minutes of listening, I came away impressed. Listened to Heifetz's rendition of  Tchaikovsky's Violin Concerto, Miles' Kind of Blue, and Krall + Bennett. 

To My ears @josh358 , they were anything but bright although compared to the Quad 2812 I heard a month back, they were on the cool side. The sound was very coherent, bass and upper ranges were coming from one place.  The soundstage was not as wide as I had expected, as well something weird with imaging. I kind of put those down as not properly set up. The sense of ease with which the music flowed was very nice. I am leaning towards the ML. 

With the post by @hthaller  pointing out the issue of room size/configuration, it would be prudent to consider the fit of the two speakers with my room. I have a 3.2 x 9 M room. With the Quads at almost 70 cm wide, I'll be left with 1.8 M between the inner edges of the speakers if they were to be pushed to the edge of the room. While distance between the rear wall is more critical, I wonder if the Quads might not be  squeezed, hence poor soundstaging. With the smaller foot print of the ML's, perhaps it's a better fit. And after reading @hthaller 's post, I wonder if maybe ML 9a, the smaller brother of 11a, might not be an even better fit? Cheaper, too. 

I would arrange another Quad audition before a final decision.  May have more question for @hthaller if I were to go the ML route. But thank you for all your suggestions.