I have been using one for about 4 years now and honestly I'm at the point that I want to go back to a drip pot.
Cue up the theme from the Marlboro Man commercials. Do I still get man points if I use cream and sugar but I brew my Community Dark Roast very strong?
Too many gadgets just make coffee expensive. I mean really . . . a full-auto coffee machine with cartridges. Next year they will have a high-capacity magazine for rapid fire brewing. When I go camping I have an old-fashioned coffee pot. I fill it with water and throw a handful of coffee grounds into it and bring it to a boil. Then I put a bit of cold water to settle grounds and just pour good black coffee. One pot to wash, no filters, filter baskets, or coffee cartridges to dispose of. And if I drink a few grounds, its just tough shit.
I have had a few people tell me this is why the stopped using theirs. They would see mold and slim coming out even after multiple vinegar treatments.
That Keurig will quit on you. I don't drink coffee but the wife does. I bought her one for Xmas a while back and it is in the garage now waiting for a yard sale. There is quite an extensive list of Web pages about how crappy they are. Glad you got it on the cheap. Oh and community makes k cups.