I'm building a pair of Statements but I've not heard them before.
I don't know that what drivers the Ascend Sierra Towers are comprised of, but I believe the Statements should outperform Salk Songtowers (as good as they are) due to the substantial drivers that make up the Statement.
The one quote I've read over and over is "You won't be disappointed". I think there are a few critics though - some don't like the fact that you need 18" rear wall clearance for best performance.