After half an hour of searching the web, I found nothing relevant to your question of case studies. I did however find the UXMovement article Increasing eCommerce Conversion Rates: Category Page which has an insightful section on sorting.
Sorting is rearranging the order in which a group of products is shown. For example, if you have a set of cars you’re looking at, you could sort them by price (low to high). When deciding what sorting order you should use, you can start with the defaults of:
- Most Popular
However, there are others you can use that are specific to your niche. For example, Ebay understands that people may want to find products that are ending soon or newly listed. This sorting order is specific to Ebay’s product auctions.
Top Rated isn't among the default sorting options, and I would consider what benefit that may give users. No matter which sorting options you provide make sure to add analytics to your customer behaviour. That's the only way to know on your site, and with your users.
the article also reference Nielsen Norman Groups article E-Commerce User Experience, which addresses the possible issue of displaying results. It's rare for users to move beyond page three of a search result, implying that you may need use filtering as well. Filter makes user chose more specifics, and listing only products they are interested in.