Checked my chimney today and here is what I found. I installed my liner in Dec. of '11 and it hasn't been cleaned yet. I checked at the beginning of the season and it looked good. So this is over a years worth of buildup. This is at the very top and gets progressively less the further down it goes. The shiney part at the top is where I tapped the outside and it fell off so it isn't sticking very much. My only experience with chimney cleaning was this chimney with my old dragon and a slammer install. Lots of the shiney creosote with that one. I don't have any brushes yet but need to get some soon. I think this is pretty good for over a year of 24/7 burning but wanted wanted some more experienced eyes to evaluate it.