Currently, the best way to compare store ratings is via the "store rating" column (though a 'sort by' feature is not available, as yet).
For example, say you want info on a Zest Kayak:
http://shop.resellerratings.com/PD-3...3/store-403161
The Store Ratings column tells you how many reviews each store has, with the orange checkmarks' rating indicator (the more checks, the better). To get all reviews data on a specific store, click the Store Reviews tab on the right.