Have a look at the Bike Friday Tikit. Doesn't fold as small as a Brompton, but it folds very quickly and I thought it was easier to manoeuvre when folded. Easier to wheel and fine to carry (and lighter than a steel Brompton). And much better to ride: agile but not twitchy at all. Might be a bit limited in luggage options, but it can take a front rack on one side. I wanted something for occasional mixed-mode journeys, possibly to places with hills at the other end. I went to look at Bromptons as well, but I went for the Tikit in the end.