From the early days of Miva Merchant though oscommerce, Magento and then OpenCart I have managed and manipulated my online store platforms. I always favour the open source software formats as these offer the most in customisability and flexibility of use. I am a huge fan of OpenCart and have used it to process millions of pounds worth of orders over the years. It is very well supported, has a huge array of plug-in extensions along with now being mobile optimised. I always have a project on the go at some point with OpenCart.
Currently I am using OpenCart on a project that sells a variety of graphic wall vinyl and have used it to overcome a number of difficult issues. It uses an SVG to create a single product image that with some additional coding, can allow the colour of the product to be selected from this single SVG . This greatly decreases the number of images that would have been needed for these products as each product has 30 different colour options. It also creates a more user-friendly functionality to the product pages.