I started out using the Tap-A-Draft system a couple of years ago, after getting back into brewing from a long layoff. I didn't have the cash to keg right away, and also knew I didn't want to bottle. I have an older version than kmcace, where the tap uses two smaller CO2 cartridges.
I never used it to carb - only pour. I don't really use it now, just to take to parties and such. When I used it regularly, though, I was very happy with it. I think it's a good intermediate step to kegging, and you can just keep 1/3 of a batch in the fridge at once. If your budget doesn't allow for kegging, but it does for this, I say go for it.