As someone who is constantly carrying her bike (up and down stairs to public transit) I agree weight matters. But - carrying a bike with 16" wheels is easier than carrying a bike with 24" even if the weight is exactly the same. Size is a factor in terms of how easy it is to carry. While the Helix fold is brilliant for a 24" wheel bike, there's no way it is going to be as easy to carry as the Brompton or other 16" bike for most people. Now just today I was out with my Dahon Mu Uno (which weighs 21.5 lbs after a few changes) and I definitely find the slightly bigger wheels more bulky to carry than my 16" Pakit - although the Dahon definitely rolls easily. But going up and down stairs and even up and down escalators with the bike folded (you get a ticket if you take an unfolded bike on one instead of using stairs) it would have been easier with my not-quite-19lb Pakit, both size and weight being better. But Baby doesn't go out on really crappy rainy muddy days ;-).