Ah, a lighting issue.

I too have run into this.  A set up (usually on skin) that requires more light or less light then something with a simple diffuse/specular set up.

I would like to see vendors (and some do) make two texture versions of their products. 

For one, if I am mixing characters from two different vendors, the skin set ups can be very different and I am forced to go through and manually change a lot of parameters.  I would be just as happy to start from scratch.

Two, if I am going to be taking this over into another application (such as Carrara) I really don't need all the "exotic" material shaders.

Still, I wouldn't want anyone to stop with really great shaders, just an option for with or without would be a nice touch.