I think this may have changed from earlier releases. I just bought an MX-810 from Surf at full price, in part because their website makes quite a point that by buying from them you get the fully-updatable software. As soon as they shipped my order, they e-mailed me a link to download the software. (this wasn't the public URC site and I didn't have to go through any additional registration)

As soon as I installed it, the software did an extensive automatic update, and it did another shorter one a day or two later. However, this version of the ProWizard software definitely does NOT have a manual "update" button. It's all automatic.

I later checked the public website, and the software you get when you register has exactly the same version number on the installer, so I'm guessing it's the same software, auto updates and all. (I didn't want to risk messing up my machine by actually running a second install.)

I'm sure that, for $400, Surf isn't giving people a crippled version of the software, so my assumption is that URC has thrown in the towel on maintaining two versions of the ProWizard software (if they ever really did) and that somewhere in the revision history the manual "update" button was dropped in favor of full automatic, which seems to be the norm for software these days.