We have multiple Magento sites, and sell on Amazon and Ebay. Cascade manages everything for us, we process orders and control stock levels on all portals, we can edit the product description and update the product description in ebay and the Magento sites instantly, and finally all of our data is one central location, it is saving us hours of work each week. When processing orders, Cascade prints out labels and notifies customers, much the same as other systems we have used, but the big difference is the other systems were designed as a best match possible for everyone,we had to adapt our working practice to suit the way they designed their systems to work, Cascade is different, they have made changes to our installation of their software specific to us, we can now work at optimum efficiency. I have been using Cascade for about a month now and as far as I can tell it does absolutley everything that an online business needs, and if you need something that it doesnt do, they would make it do that as well.
But the biggest benefit, that no other software is going to touch is their technical support, you can speak directly to an engineer instantly, and support tickets are answered normally within an hour, if not then within a few hours. If you have ever had a problem that has stopped customers ordering, or caused you to have to print labels manually or even stopped your products listing on a portal then you will know how fustrating it is to wait for it to be fixed.
I have wasted a year trying to find a satisfactory solution to manage orders and stock on Magento, Amazon and Ebay, I wish I had come across Cascade a year ago.