I have been using Broadcast by TechJoomla for a while and when i decided to ditch Virtuemart for a simpler, more supported cart I decided to go with Quick2Cart. I have not been disappointed.
It is pretty easy to understand and set up. Their directions are top notch. Although nothing is ever perfect for me and we had some issues with the template and a couple other snags, the support was right there for me.
I am looking forward to the multi-cart integration with k2 or the tagging system which is suppose to be in the next release.
Overall, I love this cart and my members are finding it pretty self explanatory.
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.