I spent a fair amount of time on it in RP. It looks like it's really good for ordering products in and setting aside stock for incoming orders.
There are a few things that I'm hoping for in the future, because you have to manually (no csv) create the reservations. We're eCommerce w/ hundreds of skus and many channels, so it's a bit unwieldy for us, but the initial implementation is a good start.
It does support scripting though, and we might have some use for it for specific cases with big partner orders.