I tried the v1 Brompton electric when I was at the shop (Brompton fanatic here) and the Tern Vektron v1 at the same time. I know the v2 Brompton is an improvement (couldn’t be much worse than the v1 frankly) but the Tern outshone it by a country mile. The Tern is quite a lump mind you. Both bikes are now on v2.
Six miles can be quite a commute if it’s hilly but if it’s flat and there are no other reasons you need an ebike, I’d suggest a regular one but look for a superlight if you are carrying it about a lot. It doesn’t look like much weight on paper but makes a big difference on a long carry.