However, the Dove i3 has no lug, although a
fork-based solution is available.
The Curve might be bigger (Check train operators' requirements for folded bikes).
Klickfix takes less weight (max 7kg vs. Brompton 10kg), there are more bags for the Brompton, and (I find they) are more convenient.
Too bad the K3 doesn't come with a gear hub + chain protection.