Ok then, Mudbox did improve.

But you can read in many forums (3d-coat, newtek and others) that users complain about Mudbox and its instability and that it works very weak except you have high-end hardware.

I have a few friends working with Max and they complain often about crashes. It is interesting how often I get such a Max crash complain via MSN. They are angry then because sometimes they lose work.

My last crash of a beta version of Lightwave got catched and I was asked to save my work before the software closes. And then I could even automatically send a bug report where I got almost instant feedback from the developers.
That is a bit of a difference.