thanks for sharing. I agree with the cross-chaining concerns. I don't agree with the concern about the chain skipping when back-paddling. First, one of his bikes didn't have that problem, so that is more a design and setup issue. Second, I never ride my bicycle back-paddling very fast

I think the 2x drivetrains are a good compromise (I have the SLR1 with 2x10). it eliminates front-shifting except for when I change to off-road or uphill. Once I'm in the front smaller or larger chainring i only shift with the rear. Once the hill ends or i go back to pavement, I go back to large chainring etc. Front-shifting also is smoother because of the 2:3 tooth ratio of 2x chainrings (at least SRAM does 2:3)