It can be a pain in the thumb to cut but PVC board won't warp unless you oversaturate it with glue (I tried just to see what the warping tolerances were). It is also slightly heavier than foam board (not by much) which allows you to use it for tree bases for Hinterland Forest (I used a jig saw to cut the circles).

PVC board is a lot like newspaper in that it cuts, rather than tears, easier in one direction than the other.

The other problem is that being a plastic like product you can not glue directly to it. I usually put a layer of label paper over it first.

Cool, thanks for the thoughts, guys!

I talked with someone, and they seemed to think chipboard might work for me if I glued two layers of it so I'll be trying that. I'm looking to make some large-ish buildings but wanted to see about making large flat surfaces instead of building it one floor at a time to cut down on the amount of time it takes.

Highland_Piper, how do you cut the PVC board? A saw or something equally manly?