I moved from Tomato cart to Abantecart two months ago. I was not finding the information and flexibility to configure Tomato cart the way I wanted. But with Abantecart it has been pretty smooth sailing.
The first setup is to use Abantecart with a Mosaic Supply Store mosaiyaks dot com using version 1.9. I did make a few adjustments to the products.tpl where the price will update automatically with changing product options. 

The next cart is a little more transformed to be a Computer Repair site for my business that I may sell products or services in the future. fullaccessinc dot com Having the ability to add custom HTML blocks was awesome.

I have not worked with shopping carts very much but this has been a really good product for me and really easy to configure.

Thank you Forest Edwards