"last bike evar" -- BS. Because of the reasons you listed, I see a tadpole trike in you future...

I am completely jealous of your Moulton.

There's excellent online resources for adjusting and maintaining the DualDrive. I just installed one on my Birdy (third time's a charm) -- found out that lousy adjustment leads to feeling like the chain is skating over the rear cass, but adjusting the cable tension to the IGH part made that go away. I'm a newfound fan of the DD, in my case an original Sachs with the chain/rod setup at the end of the axle.