uShop is about the most flexible cart for the dollar. Would be great to see an optional cgi or php interface to manage adding / viewing / editing cart. Would be nice to have that option for basic input with quantity field option, and maybe up to 6 or so select option fields for additional product properties. Discounts and category discounts can be done with php quite easily.
The back end of the cart is awesome, wouldn't change a thing, except for maybe adding paypal, UPS and USPS options. Just would be nice to have an additional alternative to this quite flexible cart.
You guys have a great cart and the best support!