I'm a keen weekend DIYer, so use the workmate a fair bit, off and on. On the plus side it's relatively robust and folds away neatly.
The one - in my view fundamental - flaw it has is that the main holding metal bolts on the front jaws thread straight into a softer plastic (white) component underneath. That marriage (of hard metal thread versus softer white plastic) is a fundamental holding point for the whole front clamp/jaw and it's fatally flawed in my view. It's now failed 3 times for me, meaning I'm back to Black and Decker again now for yet another replacement (white plastic) part, as the thread just goes every time. To their credit, they have been very obliging but I'd rather they fixed the design flaw (one I have pointed out!)....it would cost just pence to add a part with a solid metal thread, to match the robust metal of the bolt and would mean solid clamping for much much longer.
It must be a cost issue (or inbuilt obsolescence, if I was being cinical!) but, once the bolt works loose again, it means the jaws ride up and won't clamp solidly, which is really annoying.
Ironically I was give an older bog standard Workmate and I now have to revert to using that where a solid clamping action is required. Not ideal.