I also use a Tap-a-draft for small batches, the only problems being that they require natural carbonation, so you have to be careful not to move them or you will get yeasty beer, and the pressure varies depending on how much CO2 is left in the canister.
The Tap-a-draft would be improved if someone sold a carbonator cap for these larger bottles and an adapter for a paintball CO2 tank to connect to the tap head.