Love this grinder – I use it to fill K-cups and occasionally for grinding to brew espresso. For K-cups I find that I have to use a little bolder roast coffee than what I use in the coffee pot and we had to experiment a bit with the settings. Once we found the optimum settings, you just put a K-cup in the holder, push “start”, and you’re good to go. Both my wife and I enjoy the coffee it makes and find it to be very convenient, even more so than filling reusable K-cups with ground coffee and the fact that it’s made with fresh ground beans – priceless!I had a reusable K-cup made by another manufacturer that I like and used it first with the grinder but apparently it does not fit as snug in the grinder as the Solofill cups and it leaked grounds around the cup as it filled. Our favorite for use with the grinder is the K3 Gold for ease of clean up (tap the used, closed cup upside down on a hard surface while still warm/hot and all the grounds easily come out in trash can, simple rinse and its ready for reuse), filtration, and minimal leakage when grinding.Solofill customer service is excellent. I interacted with them via email and they always responded within a day and it didn’t seem to matter if it was a weekend or the time of day. They promptly and effectively resolved the concern I had and would rate their service among the best.I never write product reviews but in this case felt compelled to do so. If you are on the fence, buy one. You’ll be glad you did!