I bought two of the Juma body clamps - also from fine tools - but have only used them once, after gluing up a sash window. They did the job without protest but I have not used the Bessey equivalent to compare. I also saw the Axi equivalents and suspect they're made by the same people.
I also bought two Juuma lever clamps (like the Quick Grip style) and they work as intended.
FWIW, on my limited experience I would happily buy other Juuma clamps - the Bessey's are overpriced.