A few years ago Ronnie Kovach (ESPN Outdoors) and a rep from Eagle Claw filmed a show at the resort I work at, while they were there, the rep called all the guides together and gave us each a box of various sizes and styles of hooks and asked if any of us use "circle hooks" for anything other then halibut, nobody did, then he asked if anyone wanted to try them and only 1 guide volunteered (not me). They tied up a couple dozen mooching rigs with 2, 4/0 circles and headed out, Jeff the guide said they all started out using them but by the end of the day, only the rep was still using them, he said that instead of either dropping back to a bite or reeling which is what we instruct guest to do, you have to basically stop reeling or reel really slow to get the fish to take the bait which was causing them to miss alot of bites. They did catch some and once they were on they usually stayed on but he said the catch ratio was pretty low compared to the "Octopus" hooks we typically use. Jeff told me he thought they would probably work pretty well for a wide open silver bite where the fish hit just about anything in the water but he wouldn't use them for fishing kings.