From my experience, 2 week rotations were a waste of time. The usual response I got from residents when I told them I was going to be spending 2 weeks at their program was "oh, that sucks...."
It's tough to get to know everyone well during a month rotation let alone 2 weeks. On the other hand, if the program ends up being a bust and not what you expected, it's nice you didn't waste a whole month there.