Quad vs. Martin Logan?

Most of what I could add to the original question has been responded to by others, however no one, that I noted at least, has touched on one of the differences between the Quads and some of the others. Quads act much more like point source speakers than Sound Labs and Maggies, both of which can add more of sense of height, similar to dynamic linestage speakers, which is missing from the Quads unless you have a optimal set up. Personally, if I had the bucks and the room, I have those bigggg SoundLabs.

I own a pair of the smaller (ISIS) Innersound speakers and before I bought them I auditoned the Martin Logans, Quads and Magnepan 3.6Rs. Never heard the SoundLabs, but haven't read anything negative about them.

I chose Innersound because they integrated woofer to panel better than Martin Logans, played louder than the Quads and were more available than the 3.6Rs (At the time there was a 6 month wait for 3.6Rs). My overall preference/ranking of the 4 is:

Magnepan 3.6Rs
Innersound
Quad
Martin Logan

You need to listen to as many as you can, and don't forget things like associated equipment, room size and WAF (if appropriate)

Newbee, I'm right there with you. Those and the Maggie 20.1's are what I covet for my "ultimate" media room. I plan on adding one to my house in 2yrs under the guise of a "Gameroom". Don't tell my spouse!!

Same experienced I had as posters above for the Martin Logans. I was a fanatic (from Aerius, to Aeon, and then Ascents)until set up (TT, cart, preamp, amp) got better. The woofers inability to blend with the panel sticks like a sore thumb especially in Classical music genre. Maybe it is better than the maggies (disclaimer: I now have a 1.6Qr and happier)in some ways (although I cannot think of what at the moment) but the maggies will step all over it in terms of cohesiveness!

I never heard the Soundlabs nor the Quads so I have nothing to share for them.

Had Martin Logans. Now Innersound. No comparison. Innersound by far.
I do agree with Duke's fine presentation. Regarding the rankings mentioned, I believe the Innersounds are only bested by Sound labs.
A point worth consideration is the effect of climate on electrostat panels. My Martin Logans suffered in high humidity.
Innersounds "Ultra stat panel" is said to be immune to dust, humidity etc.
So far I have found the claim to be 100% true.
I am not sure about this issue with the other speakers mentioned.
Also, Innersounds do play loud and usually come with an external crossover/bass amp.
This feature gives some control of room conditions and allows for very good bass integration. The added bonus is the ability to bi-amp. As Robert Harley states in his book,this may be the best of both worlds . Solid state for bass and tubes for upper freq. (not an exact quote but close)
I have found this to be the case.
Down side- A smallish sweet spot. A fair trade off for me.