Terraclips + Miniatures = Ridiculous
If you haven't seen Terraclips yet, here's a look. I bought the Streets and Buildings set. What's shown is only about 60% of the Streets set; I haven't even punched out the Buildings yet.
They are not Lego bricks; they don't go together instantly or fit perfectly. You need to plan a little before you start throwing things together. The layout shown took about 15 minutes of forethought and an hour of assembly (and that's cheating a bit, since it's a simplification of what's on the Streets cover). Also, the raised levels do not attach to the walls below. This is a feature in that you can lift them off and manipulate figures underneath, but it's less visually appealing than I'd like (notice the slightly levitating tower in the background).
That being said, you can create just about any cityscape with these two sets, up to 3'x3' in area and several levels tall. It should make skirmish games like Song of Blades and Heroes tremendously more fun. Not to mention diorama building. Check out the crossbowman near the stairs, who just realized they are being outflanked.