The Fly mate is a decent vice, and i used one for a few years. However, i found it useful to fit an approx 1" thick piece of wood between the top of the clamp and the desk, just to bring the jaws nearer to eye level. Then i got fed up with having to clamp it to the desk anyway. Then i got fed up with having to deal with 2 screws to adjust the jaw gap. Then i got fed up with the O ring wearing out and snapping. All that said, it is a decent, true rotary vice, when you swivel it the hook remains level.
I rectified the clamp issue by buying a separate pedestal, i think from here:
Yorkshire Game Angling VICE ACCESSORIES
The one shown on the link is not the one i bought though. Mine was a heavy cast metal base, and slightly ill fitting! It's all back in the box now but somehow i still feel the need to keep it!
Alan