What was the best part about using Shopify?
Extremely easy to setup, design, and use. I've used at least half a dozen shopping carts, and this has the best of all worlds. I build ecommerce websites for a living. I've mainly used self-hosted open source software like Magento since it gives complete control and is customizable via the templates, extensions, etc. I've always felt hosted solutions were limiting, but not with Shopify. I customized a Shopify template extremely quickly, having no prior knowledge of their templating system and language. It was that easy. They also have a ton of plugins. So, it's almost completely customizable, with the added advantage that they take care of the hosting, PCI compliance, updates, support, etc.
What would you change about your experience with Shopify?
I wish it had easy set-ups and functionality for incentive-based items. We give free products on our store with customers who sign up as monthly members and I wish there was an easier way to make a product 100% free with a code. Right now, you have to navigate through making an item free by setting parameters based on price, shipping, etc.
Overall Feedback
Shopify is probably the best, easiest, and most robust ecommerce platform you can choose. The only thing you'd be missing vs. a self-hosted cart is that the checkout page will be on a shopify domain, not your own custom domain. Many merchants balk at that. But I think it's a really small tradeoff that most customers never notice, and you save a LOT of headaches setting up your own credit card processing and jumping through PCI compliance hoops. My 2nd choice would be BigCommerce, which I've never used, but from everything I've read and heard, Shopify is a superior choice... at the very least, a very safe choice.