Two months ago I upgraded from Vista to the Expression. For many months I was trying to convince myself that I'd be happy with Impressions, but within 5 seconds of hearing the Expression demo at the dealer I was hooked! The amazement continues, and continues . . . . These are better in every way! The sweet spot is larger and more forgiving at the boundaries, meaning the edges are a softer blending between sweet and not-as-sweet. The woofer integration is very good indeed! The ARC calibration works very well, simple to execute. I've very recently discovered that tweaking the bass stronger yields major dividends in dynamics, in addition to the expected fullness. This is a new experience for me with electrostatics as I'm used to having less impact from the panel in exchange for clarity, but now I don't feel that I'm lacking anything at all. I've currently positioned the panels about 40" from the front wall, less than where the Vistas were, and they sound brilliant! I will say that the Expressions definitely benefit from wider and taller absorption, partly because they are taller, but also because the sound field is wider. So on the front wall behind the Expressions I've got floor to ceiling absorption panels which are 30" wide and positioned in the first reflection area (between the speakers) more than a foot beyond (towards center) an actual mirrored reflection. Once I did this all rear-wave problems went away! The sound is gorgeous and I simply can't get enough! Sorry for all the exclamation marks, but they are well deserved!! Happy Customer!