I understand Dropbox acts like a shared folder on a network, and I'm really not comfortable with that taking place if Dropbox is on a server somewhere outside of our home network, which resides behind a router.
I think what I will end up doing is getting Astro onto the Vox first to serve as a file manager, and while I'm waiting for my Vox, download the apps I want onto my laptop. I can put them onto the Vox either by physically connecting it to the laptop (and I don't mind doing that, as I'm quite used to this anyway with my Sony 650) or using the SD card I bought today.
Maybe for funzies I'll start downloading tonight.