i have one, the k cups are "ok" but i use the refillable single filter and just buy foldgers or whatever i want. I also use it for instant hot water for tea. Celestial Seasons makes quite good tea in a K cup, but the tea bags are quite a bit cheaper. i've been using ours for over a year now, never had to descale. I use only RO water in it, since we have a RO filter for our fish tank.
we got ours at sams for 40 dollars, i guess we got lucky!