I have only good experience with Vanbar in Carlton.
I tried Vanbar on Joachim's recommendation, and have to say I'm quite happy with the result. E6 in one lunchtime, pickup the next - haven't tried C41 yet. And they are easily reachable by tram from the CBD within a lunch hour (Carlton store, not North Melbourne). I guess it boils down to convenience - where you are coming from and how you get there.