Hey P1R, LTNT! :-) I'd be interested to see how these programs actually do this. I experimented with QB integration for quite some time and the problem is inherent in QB. Following their documentation, I was able to get the IIS files to import, but the problem is inventory items don't have their own "list" category. All inventory items go into the standard "item list" along with "other expenses . . . . " etc. For over 1000 items, it makes a real mess of things.
Secondly when you attempt to import daily inventory changes, it doesn't update properly. When you manually enter inventory changes in QB it alters related accounts in QB. These changes don't occur when importing daily inventory changes via the IIs files.
This is also the solution we arrived at, "daily sales." Using QB 2007 retail here.