our daughter to CRT the first time when she was three. She enjoyed and had some memories from the experience. The next time she was nearly four and really remembered it. I don't know how much she would have gotten out of it going at two. I suspect not much.
We have never been to Askerhaus. Our daughter enjoys CRT and there seems to be something special about her riding the carousel just before lunch. I considered Askerhaus at one time, but since they added the photo (Which would have bought anyway) and the price differential is lower, it's CRT in June '09.