I agree with what Flyboy2160 is saying about triangulation, but at the same time I do like the Castro because it looks cool.
The classic Moulton F frames seem to be a strong design although it doesn't look it.
I much prefer the Moulton spaceframes though since they look frail but are proven very strong.

I used to hang in the road forum until I was mocked for asking why road bikes don't have thru axles (many do now).
So those clowns may be the technically incompetent people the Castro will win over.

Unless carrying a bike often or checking it as luggage; I am more relaxed aboout trying to weight weenie my bikes.
I have a 6kg Dahon Dove but much prefer riding a 18kg fatbike.