I've never co-written with anyone, heh. The prospect seems rather painful to me.
If you have the right writing partner, it is a good thing <img src="/ubbthreads/images/graemlins/smile.gif" alt="" /> Moreover, you really do learn far more about the craft itself that way as both of you have to really understand what you are doing.
The only way to work with a writing partner is if you share the same vision for a story/characters, though. Too much compromise, and the vision is lost. Your story would then suffer.
