Hic,
the 1521/1511 duo is very fine indeed. They get fairly close to the 1621/1611 duo I think, although the big brothers are a bit more airy and slightly more detailed. Unless you compare them directly, I think most people would live happily with the 1521/1511 duo.
Also note that this duo was hailed as Digital Product of the Year in TAS.
I haven't played around much with powerchords yet, but I'm about to begin soon. I'll add a note to my virtual system whenever I get to it!
The main difference between the four models of radialstrahlers (121, 116, 111, 101) is bass and room ambience. The mid- and upper range are identical (same drivers). The 101 has a omnidirectional bass driver which is very special indeed. The 111 and 116 are the same apart from the 111 using larger woofers (and consequently a larger enclosure). If your room can handle it, this is the model to pick. In ordinary rooms the 116 is the model that'll work best. My room isn't that big (5.80x4m, 2.40m high) and in here the 116 really shines, with no lack of bass I feel. :) The power amps you have are suited for both 116 and 111, so you've hit the right model there. The 101's really want the larger amps, 9008 or 9011.
If you can borrow the 111's to try them in your room, I strongly suggest you do! You'll forget all about the Wilsons, I'm sure, hehe.
