What so special about electro-static speaker

electrostatics have several advantages over cone design. they have less "cabinet" resonance and more coherency.

usually, within their range they tend to render the timbre of instruments more accurately than those of cone designs

Kal is correct. Maggies are not electrostatics. If by stats one means Martin Logan, I would have to agree, nothing special there. Quads are far better. As far as maggies go, you probably didn't hear them set up correctly. They do take some time and patience.

Oz

electrostatic speakers tend to play certain kinds of music well, but generaly, if your preference is rock or blues, stick with dynamic speakers. I've listened to several Martin Logan models over the years and none of them were able to play Metallica like a good similarly priced dynamic speaker can. Also, on some designs, when you listen to music with fast bass and explosive dynamics, with a smaller power amplifiers, the bass driver can lag behind the panels a bit, creating a weird effect. This problem's been battled with by manufacturers of electrostatic speakers, but I haven't seen it being completely resolved yet.

For light jazz or classical music though, most electrostatics will do.
Just what I observed during some listening to electrostatic speakers.

But they do sound good when you feed them the material they like to play.

dynamic speakers are still my preference.

If you can live without deep bass and loud volume, good electrostats like Quad do many things exceptionally well. They tend to be large and fussy about amplifiers.

Can't speak for the top of the line 'stats such as Soundlabs but the few lesser expensive 'stats I've heard were fast and detailed but lacked timbre. They had the bow and strings of a violin but not the wood. Same for piano. Anybody, feel free to contradict that.

I haven't been fond of Maggies until I heard the 3.5's (maybe 3.6). Those were excellent at moderate levels. Then again, they had proper amplification and were set up in a good room. I think some must have been broken.

For either type of wide-range planar, forget the budget models. It's not a technology that can be done cheaply AND well. They can be extraordinary and I do own planar magnetic hybrids. IMO, dipoles have more ambience with live recordings. Good speakers don't sound impressive, they sound natural.

Dynamic drivers have a inherent "weight" to the sound that can be comfortable but probably not as accurate. That said, most recording studios use dynamic near-field monitors and tailoring to those would be automatic.