This is the best so far, but far better than the k-duo. Forget about the full coffee pot, the k-duo takes forever to warm up and uses far more power than any other Keurig.
That said, this machine uses far less power when warming the water than previous machines, which is nice... less circuit breaker problems.
The four injection slots instead of just one does provide a better flavor with the coffee. Not sure why (same amount of water), but it does.