[slantyyz]

The Unifi cloud stick isn't that much more expensive than a PI, and is probably the least amount of work to set up a dedicated controller.

I use an Atom based PC stick that I had lying around to run the controller (on Windows) and it works great.

[technofiend]

I mistakenly thought the cloud key ran a lesser version of unifi than the distribution found on their website, however googling around implies it's the same version. So I suppose budget for a cloud key or a pi. A raspberry Pi 3 is 64 bit, runs Fedora natively and can serve up other functions beyond the key. So I lean towards the Pi but if they're functionally equivalent I suppose it's down to personal preference.