hello we have been thinking about clickcart at this time too
I like it you can connect with joomla and demo seems be good too
but the amin has far from cscart 
I think is not so confortable like a cscart
shame is they do not have a trial version and I was not able to find demo site wiht joomla integrate
I tried the install script on nginx and everything went smothly but without licencion key you can do nothing