As much as I like the look of the MDF stuff, I don't think it'll survive very long. The other MDF gear we've got has lasted pretty well partly because it hasn't been used very much.
I reckon we're better off going for something along the lines of the Pegasus plastics, or something like the more heavy-duty (I think ceramic? materials aren't my strong suit...) ruins that we've picked up in the past. They will be a lot more expensive though, and could potentially do a lot more damage if thrown in with plastics/mdf scenery.