Thanks for your responses. I had the Rowland 302s driving Eidolon Diamonds and thought they were a very synnergistic match -- in fact somewhat tubey. Unfortunately, I sold the Rowland with intentions of going SET. Prior to my Rowland/Eidolon ownership, I had a pair of WP6s driven by Art Audio Jotas and were just wonderful. The Jotas (with VV32 tubes) produced about 22WPC which certainly didn't have the last word in slam but produced such beautiful mids and decent lows and highs.
I actually now have the Air Tight ATM211 which produce 22WPC. I've had them for a week and initially thought that they were grossly underpowered but are now starting to grow on me. They're wonderful amps but perhaps not the best match for the WP7s.