I just came back from Magnolia HiFI and I'm very disappointed. I was ready to bring home a new pair of Vistas but when I auditioned them for one last time they sounded flat and muffled.
That is a very interesting statement, because technically, Magnolia is NOT an authorised "ESL Series" dealer, they are only scheduled as a "Design Series" dealer, meaning they carry the small subs, the in-wall HT speakers, the Frescos, and the Clarity and Mosaic.
How a Magnolia got their hands on a pair of Vistas is someting I don't quite understand, but unless they are different from the Magnolia stores in MD and are an "ESL and Design Series" level retailer, thy must have special ordered them or something. It's therefore not surprising that they don't sound good, because they haven't been properly trained in setting them up and driving them with the right gear.
I've heard the Vistas at Tweeters (ESL and Design) and Soundworks (Signature Dealer), and I thought they sounded very nice. At Tweeter they were being driven by a small Krell amp, and at Soundwerks they were being driven by a big Ayre amp. They were set up correctly at both dealers, and were being driven by respectable amps and front-end gear. I've always thought the Vistas sound pretty good--like a much more refined and smooth Sequel. not nearly as much "punch" as the Vantage, and nowhere near the silky goosebump-generating realism as the Summit, but pretty darn good!
I think part of the problem with your Magnolia experience is that 75wpc probably isn't enough juice, especially if it was from a "home theater receiver". With most receivers, 75 watts isn't really 75 watts--it's more like 50 watts, with 25 wats of really limited and sloppy headroom.
That, and I really doubt they had tehm set up correctly. The Magnolias I've been in are really just glorified "box stores", and most of the folks there don't seem to be more than high-ticket Best Buys salesmen.
If they won't let you take them home and try them with your gear, ask them if they'll let you bring your amp and preamp in and hook them up in the store. And be sure that they are positioned correctly. Having them positioned right is half the battle with ESLs. If they are't angled right, and the right distance from the rear wall, they will sound flat, or bloated, or lack detail, or muddy. But when you get them lined up right with the listening position, they will snap right into focus!
Good luck!
--Richard C.