Thanks, this is good to hear. I may then look into Chubby again. Its wheels and overall user-friendliness were indeed superior to the Bike Friday system. Weight-wise it may be tight for me as I built up my Brompton so much that with a heavy-duty lock it hovers around 17kg. Within the US system I did take on the Brompton as a carry-on, but I would rather refrain from doing it again - too much stress for my taste.
my P6RX Brompton fully equipped (but with Russian-made titanium rack) weighs 13.5kg. This leaves a little over 3kg for equipment, which is not much. It is left to see how much the helix rack and mudguard weigh. With the recently published measurements, I don't expect the saving to be significant, but even half a kilo could be substantial inn bike touring!
BTW, which version of the Cubby do you have: 3 or 4?