I don't know about your area, but I live in a place with many bike paths that do not have a change in elevation greater than 5% by design, but which also has some moderate hilly areas on the regular roads. The Brompton is fine for the bike paths, but for the regular roads, I wish I would have gotten the granny gear.

This seems to be such a big issue for so many people, I don't know why Brompton hasn't incorporated this into their overall design. For as great a bike as it is, gearing is the one major issue they have never completely addressed. Even on a flat surface I almost NEVER use the fifth or sixth gear, and I'm a weightlifter from a family that has professional athletes in three different sports. Brompton shouldn't just offer a granny gear option, all six gears should be lower.