I always thought of offset wrenches as like this type.
I have just one of those, and I use it for the brake pressure switches that make the tail lights come on for my 911. That style of wrench makes it a lot easier to replace them.
As far as the wrench in the OP, I would say it gives a little bit more torque for the user if the nut is slightly off center. Not much, but a little more lever action.