OK I tried the AB switch that routed my fronts between my Rotel 2 channel and my 950. The degradation was beyond words. Maybe there are "high end" AB switchers out there, or its just the nature of the beast.
Then I tried what you suggested and connected the 950's front through the Rotel. I was shocked by how much better music sounded in 2 channel. The warmth, ambience, weight, accuracy was all amazing. Except that there was a bit much energy in the upper mids which made extended listening fatiguing. But minus that problem, both pre's together sounded better than each seperately.
But alas switching to HT even after recalibration was simply aweful. And since HT is the 950's strong suit, I guess I'll just have to find another solution for 2 channel. Mabye its time to pop for the Sony TAN9000ES? Or the McCormack TLD-1 with HT passthrough. But at the moment we're saving pennies for the new HT projector.