Hey Grishnakh, you should make some more!
I did modify some of them to have different storefronts. a bunch of the smaller ones were made with Evans Model Builder. The McDonalds was made from images taken from internet screen shots, then copied and pasted through MS Paint.
The best thing about paper/foam core buildings is they can stack and store inside each other, will not break if dropped, and best of all can easily be duplicated or modified to make different buildings. They also look very much like city backgrounds you see in the comics so the focus stays on the Superheroes.
Kim