I have a Brompton and it’s a great bike. It really shines in three circumstances:
mixed mode commuting where you might ride for a bit then fold it up and take it on a bus, car, or, train and then unfold and ride again at your destination
in commutes where there’s no safe storage so you have to fold it up and put it under your work desk or you want to keep your bike in your tiny London flat
for trips where whatever you want to carry can fit in the front bag, which can be quite capacious
As a regular commuter, it’s ok but:
- there’s limited gearing range even on the six speed
- the six speed with the high handlebars is the most comfortable but that configuration of Brompton is actually quite heavy for its size
- the smaller wheels will make cobblestones feel larger
- there is space for a rack and panniers but they’re not the best as any sort of panniers interferes with folding
- thieves know that Bromptons are expensive.
I commuted for a while on my B. It was just a 3 mile commute on flat ground so the two speed was fine. My previous town was known for bike thieves so always having my B with me, even into grocery stores on my way back home wasn’t a problem.
However, my regular commuter which is a 1970s mixte road bike is all-round better as a commuter. It’s lighter, faster, more comfortable, has better gears, and most importantly, I’m not constantly worried if it’ll get stolen or rained on.