When Channels releases its DVR component, this will be a killer solution.
SiliconDust is nearly a year late on their DVR capability for the HDHomeRun (they currently sell a pre-release version for $60/year). And the Channels developers decided to split off and build it from scratch. But they have yet to announce availability.
So to get similar functionality, including iOS, AppleTV, and other device access, Tablo is the currently available option. I've had Tablo for about 2 years now and would rate it a solid "OK". Nothing great, but does the job, albeit pretty slowly.
Once Channels DVR hits, I think I will dump the Tablo.