I agree, except for the kicker, "... save for the folded size..."; That's Brompton's killer app, its raison d'e^tre, there is no other reason to own a Brompton or brompnot. I wouldn't. If I buy a brompnot, it'll be due to visiting a country where they are no more than 1/3 Brompton, I use it for light touring on the trip, and then fly home with it completely hassle-free with zero disassembly required to meet checked bag size limits. And even then, it's not going to get used much at home, except for very rare air travel for me, for exactly the reasons you stated. So it would be mostly for a) not having to transport my 406 bifold at considerable packing hassle at both ends and lots of suitcasage, and just buy a bike onsite, and b) future air travel. Around town, even train travel, just not needed nor wanted. Although it may be an opening for asking out other cute Brompton owners... nah, they'll still think of me as a "creepy old guy", that always hurts.

Plus my 406 bifold already gets me tons of attention. "Is that electric?" Don't get me started. But fully panniered as a townie, it gets a lot of "Cool bike".

EDIT: I would also add, if I lived in NYC or other place where I needed a "frequent folder" that carried great, I'd own some brompton shaped object. I live in a 3rd floor walkup, and carrying up my unfolded bifold with loaded panniers is near my limit, and folded, not much better because less bulky but I can't spread the load over two hands. In the NYC subways, I don't know if there is a wheelthru turnstile, or whether you need to lift it over, with my bike loaded that is big weight. A brom and backpack is easier. So for tubey cities, which is what it's designed for, it has merits.

But dang, it could use some improvements.