I have only fished 2 or 3 of these, but when I have the fishing has just been awsome. Old quarries have some huge cats in them. I think this is because alot of times it is harder to get permision to fish these for some reason (In my neck of the woods anyhow). Also, because when many of the old quarries started to fill up the most common pioneer fish were bull head and a wide varriety of sunfish, chubs, and blue gill. So, by the time someone decided to through a catch of channel or flathead in the quarry these bull head, sunfish, chubs, and blue gill have already been thriving for years. This (thriving bait fish population) and minimal fishing presure is why I think these fish also grow exceptionaly faster. If u have an old rock quarry in your area that is rather secluded I strongly suggest u give it a try. GOOD LUCK!!!!!!!