anyone offer opinions on X-Cart Gold shopping cart

Hi, At the place I'm contracting I snuck in the use of Smarty with an app I'm developing and the word leaked out. Well it turned out the boss has been looking at shopping carts and he liked X-Cart and it uses Smarty and so now since I'm the Smarty *expert* :) he wants my opinion about this shopping cart. I've written enough carts to know that there is no easy answer. I'd always suggest using an existing cart if it were evolutionable without turning the developers into cavemen. Hoping I can spare some work and get some good comments here (about X-Cart). Thanks, Peter