Brompton owners

I went for 2-speed due the weight-saving, though it's not a major difference.
I wouldn't go for 3-speed normal gearing as its too high for stuff a brompton needs to do.

3-speed -12% looks the best to me
https://brompton.zendesk.com/entries/22354981-What-are-the-Brompton-gear-ranges-and-ratios-

+1 for 2 speed.

As i wanted a brompton for the transportability, the lower weight was a + point. I don't really care about riding fast on one - they're essentially pootling bikes, so 2 speeds is fine.