For the past several months I have been riding virtually everything in the middle ring here on Brush. I went into the granny one time up at Mountain Lake and it messed me up :).
At first I thought I just try it to force myself to work harder and to simulate a tad bit what single speeding might be like. Middle ring and big cog is a fair amount lower than what single speed gearing though. My expectation was that my legs would get blown fairly quickly and it would turn into a grind on the climbs. However, I've been pleasantly surprised that it's doable and even made me climb much faster.
One reason it works is that my bike seems optimzed for the middle ring more than the granny. I've experienced this many times where the bike just lags in the small ring but tightens up in the middle. Another factor contributing to the success of this riding has been a new found technical capability that has been fostered from riding the rocks up at Mountain Lake
A week after riding up there I came back to Brush with this surging stutter pedal stroke on some climbs and technical situations. I was throwing the bike forward with each pedal stroke. When my right (strong foot) pedal gets to the top of the stroke, I'd thrust the bike forward and move off the saddle a hair performing a mini forward bunny hop as the pedal reached the forward position.
I was thinking that this type of movement would just take me anaerobic too fast, but for a short period I can pull it off. The net affect is that it saves my legs from blowing so I can keep turning the bigger gear without it becoming the grind. The ability to just slightly spin the gear vs mashing equates to good climbing speed.
So my experiment has now turned into a goal to try to keep doing it. Just for kicks anyway.