The UI of their platform was very intuitive, allowing me to do most things I needed without any training or assistance from support staff (which they were quick enough with).
They also had an excellent knowledge base which helped solve issues quickly for our small business customers who relied heavily on us as consultants/advisors in implementing eCommerce systems at other companies. Their customer service team could have been better trained to handle larger scale projects where we would need more hands than 5 people can provide. We used them primarily as a consultant to implement new products that didn't fit well within existing ERP platforms; however, once implemented it worked great!