Avalon Ascendants - How is the treble?

Avalon Ascendants are on my list of speakers to look into, but there aren't any nearby to listen to. (Houston, TX) From the few descriptions I've read, they sound like they would have lots of detail, and yet that they are somewhat laid back and non-fatiguing. My ears seem to be easily fatigued, especially by anything approaching brightness. I'm living fairly happily with some Harbeth M30's, but might enjoy something with a bit fuller and more detailed bottom end, in particular (although I recognize that different model Harbeths should be included in my "must listen before buying" mix). The Avalons seem like an intriguing mystery to me...very well regarded, but not a lot of concrete information about their sound. Anybody have any comments?