Crap. The spec page I linked hadn't loaded completely into my browser for some reason and I thought I'd scrolled to the bottom before posting the link, but I hadn't. Yes, I can see the "secure rsync"
When i said the original comparison had errors, I wasn't talking about the one I linked to, but the one linked to by the previous poster. It listed the warranty as 3 years for both products, where we know the "Business" has a 5 year.
I would argue that from a marketing perspective, a "diskless" product is more a business/industry product than a home product. Most consumers wouldn't know how to go out and buy drives to stick into and configure a NAS. However, that's the perfect solution for an IT professional.
They really should not have named the Pioneer the same name as the business version. A better name would have omitted the "Pro" from the name, because in all markets, "Pro" means professional. Whether someone uses it in the home or not, that's not the connotation of the name.
I'm using it in my home office. The price is already somewhat ludicrous for the Pioneer, let alone the price of the Business version pre-populated with super marked-up drives.

I will definitely request that upgrade be made and I hope someone is kind enough to oblige. Thus far I have not been successful at all in getting the rsync backup feature to test with anything but a root path to my Mac. A guide on the subject would really be useful. I'm pretty sure I can easily rsync from the Mac to the RN, but I'd really like to have the schedule handled on the RN side in a pull fashion, if for no other reason than to have all my NAS-related backup scheduling in a single interface.
Thanks guys for the replies, much appreciated.
As an aside, I do remember the Infrant web site had a lot of great information and now looking at the Infrant rsync document I'm painfully reminded again about Netgear POS web sites and documentation. Really, what happened since the acquisition? Why are the products now so under-documented? I was really unimpressed with the complete lack of useful documentation that came in the ReadyNAS Pro package. It was totally not appropriate for a diskless unit, telling readers instead to go online to read the user guide. And that guide is again another story.. Ugh. Not very good at all, with having to reference "factory reset" procedures to install disks in a unit that didn't come with them in the first place.