We have had a few large games so far, the biggest being 8ft x 4ft though. We are currently in the process of creating a 6x8ft perminant Apoc board. All the boards at our club are framed so can be used in a multitude of gaming arena's. You should check out our boards of our Facebook, fortheknowledge gaming
U r correct with the other tile shapes as well although and for one off City Fight tiles are a good idea. The great thing with the City Fight board is that we can just keep adding to it.
Currently in progress is a 24" x 24" tile with the one large building on and several other standard tiles that will create a wall defence.
I will get more pictures up this month although they will be just work in progress
Have a good day Nagged