I have the tap a draft system. It's fine for what it is but is nowhere near a real kegging system. I used a lot more co2 cartridges than indicated to keep the beer dispensing properly. There are conversion systems to use a paintball co2 tank which I'd probably be looking into if I didn't just get a kegging system.
I probably spent close to $200 getting extra bottles, taps, co2, etc for the tap a draft. This week I got a full kegging set up with a keezer and four corneys for $350 from CraigsList.
So, the tap a draft isn't a great value in my mind but it is better than bottling.