6 years later and I'm resurrecting this thread...
Years ago I changed from the Legacy Focus 20/20s to the Legacy Whisper. Since the posts above I went from the Dreadnaught as two channel amp, to a McIntosh MC-352, to a Krell FPB-300c, and finally to a pair of Theta Enterprise monos. Each step along the way was a clear improvement.
From the Mac to the Krell, the Mac excelled at more simple acoustical music, and seemed to be ready to go right away. The Krell at first seemed stereotypical Krell, harsh and lean, but after some warm-up it really opened up. With the Krell I found myself listening to all kinds of music from the simple acoustic stuff to much more complex and busy stuff, and it remained crystal clear and wonderful.
Then came the Enterprises. By this time I had the Whisper speakers, and had a modified CDP which was also a huge jump up in performance. When I installed the Enterprises, SACD and DVD-A suddenly became clearly the superior media. Before the difference between hi-rez and redbook was "ho-hum", but now it was clear...pun intended. Suddenly it was much more like an open window between myself and the music.
Now comes the relevant part...finally...
A while back I connected the Whispers to the Dreadnaught and found that the bass was surprisingly NOT lacking at all in comparison to the Krell, or the Enterprises. This I cannot explain. Years ago with the Focus 20/20s, the deficiency was immediately noticeable. With the Whispers however, it was not. I will add that the Enterprises still did a better job than the Dreadnaught though. The overall presentation was much less veiled, like that open window I mentioned, not that it seems veiled with either amp, but it simply sounds better with the somewhat controversial Enterprises. I really like the Enterprises.