Miva Merchant

We used MIVA for almost four years but left them in September 21 for Shopify Plus.
It became too costly compared to alternatives like Big Commerce and Shopify, and they've really fallen behind as a platform. Their management is stubborn, refuses to listen to reason (or else just flat out didn't believe their customer). Hedge fund money seems to have ruined them. Too bad. I was a very loyal customer for years and I still respect their great staff.
Shopify has many more features, is much easier to use, and costs us 1/3rd the monthly rate we were paying MIVA.

If you use Miva Merchant, make sure your hosting company has lots of experience with them. - I have used miva merchant for years and the problem I have always run across is that the hosting company MUST be an expert using their miva merchant software or you WILL have problems. Lots of hosting companies claim to support miva merchant, but in my experience most will not waste too much time solving all of the miva problems. So, be really really careful if you go with Miva that your hosting company has lots of experience with it.