Yes I do. The reason is more a traditional one anyway. I once started working with 3D using Raydream Designer and I just followed the product line and its successors since now so I am still with Carrara today although I tested many other apps during the years of course. The second reason is the already in this thread mentioned price. It is quite cheap but has a wide range of common functionality. Sure a hollywood highend 3d movie designer may not use Carrara because it is too limited, but up to a certain quality demand it just satisfies the needs. My personal problems with tools like Blender are some details that just don't fit for me, for example the hard to learn interface of Blender. So Carrara is for me a good compromise of sufficent functional range, ease of use and affordability.