How similar are saddles made by the same company?
The only thing that you might be able to bank on is the width of the saddle.  I know specialized in particular has different widths for the same model of saddle based on where you sit bones are.

Other than that, you will really need to try each saddle to know how it's going to feel.  I have the Toupe on my road bike and it's fine for a road bike but I wouldn't want it on my MTB.  It doesn't have as much padding as the specialized MTB saddles.  

Short Answer: You have to take each model into consideration individually.