Hi Pete. Just a week and a half ago I switched from biwired DH Labs Silversonic T-14s to a single run of Analysis Plus Oval 9 and the improvement was dramatic. Before changing out the cables, my Sim Audio Moon I-5 feeding a pair of Sonus Faber Concertinos sounded thin and at times even a bit strident.
Right out of the box the difference was noticeable. The overall sound became much fuller, and almost all of the hash has disappeared. The biggest improvement came in the soundstaging. Wider, and MUCH deeper. By comparison, the DH Labs had a flat and in-your-face presentation. One caveat though. I've experienced a slight loss of detail.
I can't wait for this cable to break in. I'm not sure if the AP9s will have the same affect on your system, but they're working quite well in mine. In my system, the AP9s have proven to be a warmer and better imaging cable than the T14s.
If you're interested in buying new, contact Scott who's Audiogon username is Disco. He carries the APs, can burn-in the cables if you want to, and will give you great service. Otherwise, you'll be able to find plenty of used ones here at good prices.