It doesn't seem natural to tighten without a final clout, but I've tested the hex tool & breaker bar and a final clout with the hammer doesn't move it, so I'm totally converted. I don't carry it in the car though, it's garage use only.
It undo's with a nice firm pull, which again doen't seem natural. The only disadvantage with the hex tool is that it's VERY expensive and you don't get the bar with it.
Is it worth it? absolutely.
