Greetings Ehart -
And welcome to the wonderful world of electrostats!
There are several different flavors out there. Let me describe four of them for you, and you can see what direction makes the most sense for you.
1. InnerSound - These are probably the best-imaging and have the best dynamic impact of all the electrostats. The bass is very adjustable, which is important to get a good blend between panel and woofer. The downside is a very small sweet spot - but this may not matter to you, depending on your listening habits.
2. Martin Logan - The Martins give you a wider sweet spot than the InnerSounds, and are generally very elegant in appearance. Rather than build one or two models with lots of adjustments, Martin Logan builds a wide variety of models. It's important to match up the right size speaker for your room, to get the woofer/panel balance correct (I'll talk a bit more about the challenges of woofer/panel integration a bit later on). In a fairly large room like yours, the Prodigy would probably be the best choice, but the Odyssey still would work well.
3. Quad makes a couple of full-range electrostats. While they don't play as loud as the Martins and InnerSounds, they have a lovely coherence that isn't possible to get from a hybrid. I've owned several earlier model Quads.
4. Sound Lab makes some rather large full-range electrostats. They are the least efficient and probably most difficult to drive of them all. The have a rich, lush presentation and an extremely wide sweet spot (unique among current production electrostats). I own and sell Sound Labs.
Note that if you choose to go with electrostats, you must give them plenty of room behind the speaker. You may have to treat the backwave a bit - I like to use diffusion, and avoid absorption except as a last result.
Also, amplifier matching is much more critical with electrostats than with dynamic speakers. Fortunately, you're starting out with a very nice amplifier, and it may well suit your needs (I have no first-hand experience pairing up that amp with electrostats).
Let me describe one of the challenges of integrating an electrostatic panel with a dynamic woofer (there are many challenges involved, but I'm only going to focus on one here). The panel approximates a line source (sound radiating cylindrically from an infinitely tall, thin line), while the woofer approximates a point source (sound radiating omnidirectionally from a tiny point). Sound pressure level falls off with the square of distance from a point source, but linearly with distance from a line source. Let me use an illustration to explain:
Suppose your woofer is putting out 90 dB at one meter in an anechoic chamber. Move back to 10 meters, and the sound pressure level is now 70 dB. But for a line-source panel that's putting out 90 dB at one meter, the sound pressure level will only fall off to 80 dB at 10 meters! So what the designer has to do is voice the speaker for correct tonal balance at the anticipated listening distance. Too close and the woofer is too loud; too far back and the panel is too loud.
In a real-world room this discrepancy isn't quite as bad as the theory predicts, but it's still there. I once measured a hybrid electrostat in my room at 1 meter, 3 meters (the listening position), and back at 8 meters (maximum practical distance). At one meter, the woofer was up by 1 dB. At 3 meters, the output measured the same for both woofer and panel (no joke - and they had been adjusted by ear). Back at 8 meters, the panel was 4 dB louder than the woofer. So, at large listening distances, this speaker would sound a bit bright and forward. So I hope you can see the importance of matching the right size speaker to the room, or of dialing in the right level setting for the woofer (depending on which brand you end up with).
Finally, you asked about Maggies. Maggies are full-range planar magnetic speakers, not electrostats, though they have much in common with them. Maggies are an easier load to drive than electrostats (though their efficiency is still low and they also like lots of power). Electrostats are often a bit more articulate than Maggies, especially at low volume levels, but Maggies are very nicely voiced and since they don't use dynamic woofers, they are generally more coherent than a hybrid electrostat.
Between these five manufacturers, chances are there's a speaker that you will fall in love with and perhaps never desire to replace. Without knowing more about your personal preferences I can't make a reliable recommendation, but the more different planars you can listen to, the better-informed your final decision will be.
Best of luck to you in your quest!
Duke
