Heh, I wouldn't trust any Microsoft software where they've explicitly decided to call a toy !
Seriously though, the Jpeg resizer I currently use is also a Microsoft (Power)Toy, released as an unsupported tool that was ostensibly written as a personal project and it's been utterly reliable!
Thanks for the Robocopy tip - I'll take a look, and thanks too for the CLI script comment; it's what I would assume but I haven't yet confirmed how ImageMagick is invoked.
Cheers,
XV