We bought few
Vincita products in the past and they have been reasonable. Maybe one point to note is that the bags carrying Brompton logo in the market do not generally need to be made by Brompton, but by may be made by independent companies that got Brompton to lend them the logo. From what I heard Brompton is capricious - getting the logo can be a good sign, but some companies may find dealing with Brompton too much of bother. I would say that the latest
(don't know who makes it, maybe Brompton on their own actually) is Vincita inspired - not the other way around.