The turning radius of the chair and the dimensions of the chair can be critical.. And they are not necessarily directly related - depending on how the chair drives (front wheel vs mid vs rear) sometimes a smaller chair can have a larger turning radius. Not good! Hal thought about getting a PerMobile 500 for some of its extra features - BUT not only is it much more expensive than the C300 - it also has a larger turning radius, and is a larger chair in general. The C300 just barely can maneuver in our wheelchair van, and just squeezes through some of our doorways. We were lucky enough to get a vendor who brought a C500 to our home, so we could tell it would not work for us. We ended up with the C300, and are relatively happy with it. The elevating feature is a must, though - to save the Caregiver's back - even though insurance and Medicare will not cover that feature.