Okay, so I got the kind of deal on my Woodstock Keystone that makes you almost want to say to the seller "I should give you another $500 for this stove". But it is a used stove. Last night watching the burn closely with the bypass plate closed to use the combustor, I noticed flames still "seeping" out under the bypass plate. Looking more closely, I noticed that it did not close completely as it should. After speaking with Woodstock today, and opening it up for a closer look, I believe the byplass plate is warped and will need to be replaced. Therefore, when the cat is engaged it is only partially effective. I don't know the price of a bypass plate yet and it really doesn't matter too much given the great price I paid in the first place, but it highlights the types of issues buying used can provide. I know that the previous owners didn't really use this stove to its fullest benefit. When I cleaned out the combustor, it was PACKED with ash, in fact the upstream side between the protective screen and the combutor, was filled with an inch or two of packed ash. No way they could have actually been utilizing the combustor. The bypass plate issue is probably a result of overfiring. The rest of the stove seems fine and the combustor is in fine shape now that its cleaned out since it probably was never utilized much to begin with. But as forum members inquire about this used stove or that, it's important to remember that the operator of the stove is often much more of a wild card effecting quality than the stove model or amount of use is. With the education people get here, not only can they be far more savey buyers, but probably more importantly, they can be wise operators too!