I like the sound. It's very clean and great midrange IMO. I listened to a lot of music on them and they are great paired with a sub. I don't know what you would consider expensive, but it really depends on the speak. I listened to the Vistas paired with the Depth i subwoofer which is $3500 for the Vistas and $2000 for the Depth i. Oh, and they were on a Rotel RSX-1067 receiver paired with a Rotel 1050 dvd player.
I also listened to The Incredibles soundtrack on the Summits and Descent i recently (11k for the Summits and 3k for the Descent i). It was a 5.1 channel system so they used an RMB-1095, but they had 2 of them so I don't know what's up with that. It was probably bi-amped. It was great and I loved listening to Drum & Bass, Bela Fleck, Coheed & Cambria...pretty much anything.
I used to own MartinLogan speakers, the Scenarios, which were the entry level speakers. The panel was not large enough to cross over "seemlessly" to the woofer, and had a somewhat rubbery sound overall.
The new Clarities are a much needed improvement. They are about the same size, but the crossover is much better, and the panels are better.
MartinLogan speakers are very clean and clear, and are outstanding in the microdynamic and resolution department. The larger ML speakers are also excellent in the macrodynamic area as well.
They have a unique sound though, and are not to ever person's taste.
The true electrostatic models start at $2800 and go up to $120,000 for the Statement e2 (not sure if the statement e2 is in production at this time, as it is being replaced by the statement e2 x-stat)
The ATF panel speakers (ATF panels are made by BG corporation, they are the neo planars) start ar $1200 a pair, and are also excellent speakers. The Mosaic was just discontinued, so you may find a pair around $1000, which was half off when it was new.
Martin Logan speakers have very nice upper end detail, resolution, soundstaging, and accurate tonality. The lower level models typically have less impressive bass response, and the soundstage gets's a little less impressive off axis from the smaller panel surface area. ML's really require an audition and are usually love it or leave it.
I'll definatly take it. The Clarity is an excellent speaker, and one of my favorites in the price range. The former Ascent i WAS my favorite in the $4000 price range.
They aren't everyone's cup of tea. A friend in a neighboring town has a pair of the original generation Innersound Eros, and they seem to have better overall sound quality, will play louder, and have better driver intergration. When Innersound was making world-beater speakers for really affordable prices, give me those any day. But now... at $10,000 and up... there may be better options.
As in all things audio it's a matter of preference. I feel that ML speakers lack "soul". They don't have that certain something that breathes life into music...that's just me.