One reason I haven't obtained a feeder, other than cost, is concern about wasted feed. The CC won't venture any shallower than about 18 inches of water to feed. My ponds are very exposed to wind, and the feed quickly blows into shallows so nothing but small BG and FHM are nibbling at it. That's why I have installed feed "corrals" made of 3-inch DWV PVC pipe. The feed hand thrown into the "corrals" stays put while being consumed over a 5-10 minute period. Am I being overly concerned about wind scattered feed?
John, I've used 3 TH 70 lb feeders for a year, plan to install 2 more this year. My experience has been that wasted feed isn't much of an issue so long as the fish are interested. Even when some of the feed goes to FHM or BG rather than your preferred CC, the FHM/BG do end up feeding the CC.
Two caveats: Watch for feeding activity with the water cools. The fish can turn off like a switch was thrown. And if you have a very fertile pond -- not my situation, unfortunately -- then you should be more careful about any feed that is not eaten quickly. Could push you over into algae problems & other bad things.