I use both - was riding a Specialised Power Pro for a while, switched back to the Brooks B17 last week as it's a little bit friendlier on my suit trousers.
Genuine question: lifting up bike folded, isn't brompton's own saddle the easiest for this? My missus loves using SPDs on it and everytime I have to use it I switch it to flat pedals, makes me think anything non stock is disruptive to the usefulness .. no?
What saddles are you people using on your Brompton ? Any of you tried Road saddle or should I stick with Brooks B17/Team Pro ?