I too prefer resin or - well, basically almost anything - to plaster. However, aside from the Stronghold Terrain streets I don't know of anything suitable. Also, the plaster streets are only 2mm thick. That's why I mentioned the point about breaking in my post. This also means that the pieces are not heavy at all. A similar resin product would weigh about the same.
Still, if anyone has any suggestions for similar products I too would love to hear them!
