We're used to using the Doughty original version of these (at twice the price!) , but took a punt on the Global Truss version after a good friend in the production business spoke highly of them.
We bought around 30-40 units to use on some of our moving light hire inventory and you can't moan at all! The simple and ease of use, great design and black finish is ace!
The only real major differences between these and the Doughty more expensive version is the turn thread being tighter and not as smooth (not a massive gripe) and the finish being not quite as hard wearing. For hire use to keep with with fixtures and to send out they're spot on!
For users and hirers who require an excellent clamp at not a lot of dosh these come highly recommended!