1. You can set it at Settings-> Appereance - "Product detailed page view" - this will update the product template for all products.I just went Responsive. What a messy little piece of work that was.
Easy for some I guess.
How do I give all my products this nice new look.
Nothing under 'Settings'.
Do I have to select 'The big Picture' in every single listing one by one ?
2. It category page has a View tab - there you can set the product template for products in this category only