I have had the 100W & the 200W home to audition. Both deliver well beyond their price. The 200W has a bit more weight to the overall sound, and better bass. Both are transparent with great top-end extension.
I have owned the A400S (200 wpc) for about two months now. Impeccable sound, totally silent background, no grain, no stridence, airy highs, smooth mids. A little lack of bass in my system driving Silverline Sonatas, perhaps due to overdamping.