I zip fish about 20" or larger. The smaller ones the bones aren't too bad. I like to scale smaller fish and have the fillets whole for the grill. The bigger ones I zip because I will probably be cutting them into chunks or smaller pieces any way and zipping takes out some of the stronger red meat. The red meat isn't that bad but I think it makes for a milder flavor, IMO. If you prepare your fish without breading or batter its easy to pick out the bones but if you coat them before cooking the bones are a PITA, especially for little kids. Just my 2¢