For the "go with one", the mock-up was more elaborated. Milled foam with painted skin and details in stereolithography.
I did exactly as I said. I made a completely finished model, with all the details, fillets, gaps, clearance and features for easy positioning and assembly of each part. At the worshop, modelers complained because they haven't enough to do...
It was very different for the other model. Up to the end, the designer wanted many changes and the modeler hadn't enough time to make a well finished model. At the workshop, modelers had a lot of work to complete the model and they missed time to achieve the same quality.
The final choice is a crucial moment. Many people are involved : style, engineering , marketing. Then starts the actual industrial process . Any further style modification will now require the approval of everybody.
Here the decision is difficult, both models are equaly appreciated. Eventually, this model is selected when the design project manager says : "at least we know we won't have quality issues with this one".