Marc,
I think there are two things about co-writing. One, good, one bad. While two heads are better than one, (they are, aren't they?), in a close enviroment such as Nashville you may be able to write better songs, but two, everything begins to sound the same. A producer may listen to a bunch of good songs and pass on all of them because there is nothing fresh in the whole bunch!

I once heard Joe Diffie say he went thru every song in Nashville ans say he could find nothing he liked.

It is hard to write a good song co-writing or not. I would like to visit a Publisher sometime and listen to a good selection of songs he has signed. I think it's true that most songs have been written by more than one writer but not neccessarily with the Artist.

Ray E. Strode