I have the Thorpe drivers myself in both SAE and Metric and I love them but I have never seen ball end versions.. Still, unless you need to access the bolt from an angle, the Thrope drivers seem
to be ground to have less clearance in the socket head screw and they don't strip bolt heads unless you REALLY over tighten them. I've been able to remove loctited set screws with them, even after other allen wrenches have stripped them out a coupe of times.

Wayne