I've had both the K-Mini and the K-Mini Plus, and both of them started making watered down coffee no matter what I did. I tried adding more coffee, different brands, darker roasts, etc. and nothing worked. All the coffee this thing made lacked any bold flavor and felt like someone just filled half my cup with just tap water.
I replaced my full sized Keurig with the K-Mini due to the small size of the K-Mini fitting my kitchen better. The K-Mini is a great little coffee maker that fits my needs perfectly. I like the fact it uses fresh water for every cup as well.