Like I said, two things drove me to the Brompton.
1. Needed a bike I could carry onto an airliner and place in the overhead.
2. Had to be strong/large enough to hold me (Over 6' 2", 240's lbs).
The Brompton is seriously overbuilt. I would crack most aluminum frame bikes, much less folders.
FYI: Chinese manufacturing is now as good as any in the world. I'm a researcher for an American company that uses that, IMHO China will eventually own the Electric Car market (not my industry, just my opinion).
And maybe it's undeserved, but the resale on the Brompton, for whatever reason, makes the total cost of ownership low.