Yep Eric I think that sums it up pretty well indeed.

Although the 'red knob' twin never was a greatly appreciated or lusted after an amp, it was by far the best Fender I ever played...it had the switches to turn it into a 100W, 50W or 25W amp.
It had killer cleans, like any regular Twin, when on 100W, but when you dropped it to 25W you could get quite un-fendery, singing drive sounds from the thing.

I would LOVE to have an amp that could do that with a footswitch...instead of just adding another more driven channel it would actually really double the wattage...that would be perfect.

Because, despite how good master volume can be, the really really best guitar sounds for me will always come near the max volume of the amp, when the power tubes are already working hard hard hard. So if you always want to be in that zone, there is no way to effectively go any louder or quieter without destroying the sound...the wattage halving on the fly would solve that problem.

Hm. Actually a switch to kick in an attenuator would do just about the same. Hm. I wonder how hard it would be to build one working on a relay.