[ehaskins]

I've installed doors with that system, or a very similar Menard's carries.

Given the choice, I'd opt for it since it is easier to fine tune, but I'm not convinced it's safer than the traditional way. You still have to secure the door against unintentional movement and ensure everything is assembled correctly before tensioning.

The only "safety" feature I see is it eliminates the appeal to use an inadequate tool to tension the spring, so resist the urge to use a flimsy old screwdriver and you'll probably have similar risk either way.