Great post OP...Sonic Nuggets for sure...
I just love um. I use Nord now, but would have bought these in a second. I like US made stuff too. I want to try the Weiss, op amps. All the others are good, though I lean towards Sparco, the SS2590s with the NC modules are a planars dream... Great stuff.
They have a gain option too 7 or 14 I think... lots of goodies..
I wish them well, I'll be doing some module swaps, NC500 to 1200 maybe... 4 ohm rating is the same on both. But the 1200 are @ 2 ohm.
I drive all of mine at 3 or more... Just get to hot... Both will do 1 ohm for short burst
Regards..