:?: why oh why must you do such a thing? oh well...good for you...now we ALL know who can drive for any STR beerfest!!
With nitro taps and CO2 taps, you are just maintaining a constant vapor pressure to keep the CO2 from coming out of solution (equilibrium). I agree that they preserve the appearance of freshness by maintaining carbonation, but for 5 liters, the counter pressuring is really overkill. Who the hell keeps a 5L minikeg for 14 days? That's downright abuse and neglect. A 5L minikeg won't last 3 hours in my place with people over, so it is still just an over-priced dispenser IMO. The 5L minikegs have spouts that work just fine for 10 pints.
Check out BevMo...they always have a nice supply of mini kegs available. There are also a lot of cool mini kegerators available online as well.