I picked quick2cart because 1) didn't want to use Virtuemart, 2) wanted to use a 3rd-party joomla-stripe-payment plugin for it, and 3) it appears to be popular.
Haven't used all the features of quick2cart yet, but it's been nice so far. I look forward to using the multi-vendor feature some day, as that feature is quite powerful.
It uses bootstrap for it's styling, which is nice.
I noticed a couple of PHP Notice errors, and I contacted support, and they hot-fixed it and immediately sent me a new release.