When it comes to hook holding ability, you just found it.
The Peak Rotary Vise with C-Clamp is the C-clamp model of the extremely durable and extremely robust vise that peak has designed. For hook holding ability from size #2/0-as small as you can find, this is a one stop shop. The C-clamp holds incredibly well on even rounded tables with the tri-nut locking screw. The vise offers extremely easy adjustment for different size flies with easy.