I've used it for one client through two versions of Joomla!/VirtueMart now, and it is fantastic. The first iteration was fairly simple, but John both open to some suggestions for improvement and also to make some paid changes to it.
It's now working in the second iteration (for J2.5) and the advancements that John has made to the module are fantastic. It can now be configured to allow for signature on delivery, insurance etc, which makes it far more usable for a vendor.
John's service is fantastic and the moderate fee he charges for this module is well worth it for all the pain that it saves!
Thank you for your excellent review
I really don't think you'll find anything better than this!