Wilson Sasha 2 or Alexia for small room 10' x 17'?

I have had Sophias and later the WP7s and now Sashas in a  14 X 20 room. Going on 11 years with the WP/Sasha combo. They are simply perfect for my room. I get almost all, if not all, of the bass with very few room nodes and the presentation is all I could wish for. But guess what happens after 11 years of the same great presentation?
 Having heard the Alexias in a similar but slightly larger room, the sound with my amp and preamp was simply larger and more compelling all around with more impactful bass and more "you are there " or "they are here" feeling. I sometimes think about moving up. Having said that, I think I am near or on the edge of the minimum size room needed to do some justice to the Alexias.
 I think 10' depth (or width) does present a problem for a speaker the size of Alexia. That is, the margin of difference between the Sasha 2s and Alexias (about the same margin as between the Sabrinas and Sasha 2s) would be substantially reduced by the inability to get all that the Alexias can give. You will, on the other hand, get very much of what the Sasha 2s can deliver in your room vs the Sabrinas. The Sashas 2s are remarkable all around speakers at anywhere near their size and price range. 

IMO, in a domestic environment, there is absolutely no way to predict how a speaker will work in the room.  In my own experience, I've had small standmounts with 5" woofers produce a fuller bass response than floor-standers and much larger standmounts.  If you are buying used, you can take a chance on a blind purchase, as you won't lose too much if you sell, but if you're buying new, at those price levels, I personally would not buy anything without hearing it in my room first.  Good luck.