[fluffymunchkins]

If you get rotastak from ebay they often come in a set with lots of different cages that the person has collected over time. Even the new buy it now cages are cheaper than in pet shops. I can't say how good they are for other breeds although i agree they are not suitable for syrians. For robos they are great! although they have trouble climbing the vertical tube, i solved this easily by putting fleece inside. As the metal ladders advertised for rotastak are dangerous and Dot injured her eye on it.
Lots of people mention the fact that some compartments are round but really i haven't found a problem. The tripod section does have corners and my robo prefers to 'go' inside her toys anyway. She cannot move the rainbow runner wheel either, but it dosen't really matter.