HDHomerun Prime

The HDHomerun Prime has cableCard functionality, will the LiveTV(beta) and DVR functionality work with cable channels. Or will they only work specifically with HDTV over the air broadcast

Works fine with my Prime on non-DRM channels. Check with your cable provider for DRM channels.

The free SiliconDust Player application will presumably play the selection of channels that are not DRM protected. So that can serve as a quick check for what you will get.

With cable I recieve something on the order of ~430 channels or so. With Plex DVR / Live TV and other application I recieve about ~389 channels.

Basically Xfinity or FiOS you are pretty safe with everything but HBO, etc. With others like TWC you’ll be screwed. Charter, cox, spectrum, and small outfits are not consistent enough to know without you trying it out