I use ultracart and maybe the worst thing about it is that it has too many features.

Some parts of it that i haven't found with 1shoppingcart:

it has OTO upsells after someone buys

you can assign as many files as you like to 1 product for people to download, not only 1 file like 1shoppingcart has

you can customize the look of just about any part of the cart

they have special features like "return" which will automatcially send someone a special offer if they abondoned their cart

The integrate with aweber, getresponse, mailchimp and a whole bunch of other email services

Frankly, I can't figure out why the internet marketers dont use them.

Money perhaps? On private label deals with 1shoppingcart?

Actually I am in the midst of preparing a website that will show how to use ultracart for the information marketer most through the use of screen captures.