I have one, which I've used mostly for small metal working tasks, but bought for luthiery applications. I like it for the metal work, and the way it swivels then locks when you tighten the jaws is very user friendly.
IMO a good tool, even though I've yet to use it for what it's meant for.
Well, fancy that! Richard Arnold has one of these, and was using it at the MAC Timbers open day to hold the stair raill he has been working on. We all admired it and thought it was a really elegant design. Now that I know they are available, and cheap, I am seriously tempted to buy one!
His is visible here:
and this is the Axi one to save anyone else from searching