Used Maggies

They are really good midrange speakers if driven with top flight electronics, however, you must be absolutely on axis to appreciate its strengths. I always thought it was like listening through a smallish window.

The biggest thing I'd worry about buying used Maggies is the barely adequate factory packaging. IMO, it leaves the speakers vunerable to shipping damage. Admittedly, I've had worse than average luck with every shipper out there, but I don't think I'm being paranoid. I'd prefer to pick them up myself if there was any way possible. I can't say I found Maggies to have a small soundstage if they were set up properly with adequate room. As long as they were around a third of the way out into a decent size room room and had at least four feet on each side, I thought that bigger Maggies have a very generous soundstage. We've all got different perceptions about these things though. Your rooms footprint is a good size, but eight foot ceilings aren't ideal. About the only thing to watch out for is delaminated membrane wiring in older models.

Best to get the serial numbers and contact Magnepan. They are very friendly and helpful! I bought a pair that had been in storage for a couple years and the adhesive had broken down. Their repair service was excellent. The best part of maggies is they can grow with you and each step up provides outstanding results. I have 3.5s now using active XO biamped the sound per dollar is awesome

I think with your size room you would be happiest with the 3.6's. Make sure that the magnetic strip is attached to the back of the tweeters. Have them strapped to a pallet and shipped, try Yellow Frieght. When you open the boxes go slow the pressure can blow the tweeter.