Dob, have you ever heard or checked out the H2O Audio gear? His amplifiers are not slap-an-ICE-module-in-a-box affairs. They have very stiff linear power supplies and they sound different from other ICE module amps. His preamplifier has, as far as I know, a very unique design resulting in extremely high quality sound. While subjectively one can like or dislike his products, objectively, he is a skilled and knowledgeable designer.
Regarding negative feedback, I agree with most other end-users who have posted in this thread. In my experience, some amps that advertise no negative feedback sound very good when driving speakers that offer a benign load, but tend to sound soft and rolled off when driving more difficult speakers. While having auditioned and owned gear from a number of good designers, I've had better results with electronics that have some amount of feedback when driving my particular speakers (Avalon Opus).
By the way, I've heard the Spectron amps as well and I thought they sounded good in the two systems I heard them in.
Alan