Huge scratches somehow appeared inside our stockpot one day, so now it's non-stick capabilities are non-existent. I don't know how it happened, but it did. We've had the stockpot for less than a year, so it's pretty disappointing, especially since we haven't had any problems with our other Calphalon things, (all our pots and pans are Calphalon One, just like this one). My assumption is that someone used metals utensils without realizing it -- so I would say in general, with Calphalon One, be sure to use the correct cooking implements.
However, with all that said, I have to say too that until our stockpot met its untimely demise, it really was a great piece to have in the kitchen. I makes for really fast clean up, which is really great when you are dealing with such a humongous pot.