Smaller than advertised! 
It's a nice gazebo... tall, relatively sturdy.... heavy as anything. It looks great. 
The 10'x12' measurement is of the roof. The columns are set 8" in  so it's got a smaller footprint than I was expecting. I bought this one to replace my old, fabric-top gazebo. That one was also advertised as 10'x12', and that was the footprint measurement.
There was some damage during shipping, too. Several roof panels were scratched, two of them deeply... it'll be rusting before I know it.
Again, I like it... it looks pretty nice, but it didn't quite live up to my expectations.