We have been using BigCommerce for over 2 years now, and they have some of the best customer service and support out there. Anytime we have had any kind of platform problem their techs quickly jumped on the problem and had it solved for us in less than 24 hours in most cases. It is a good stable platform in the USA, which is also a big plus for us. I would highly recommend BigCommerce to anyone who is considering a business in e-commerce.
