I'll use em when I get the new tires etc, when the build is to that point. I had the Gorilla lugs on my old K5.
It works a little better for me because my K5 is never anywhere that someone can "scope it out" for long. I live out in the country, back in the trees away from passing strangers.... and no one would get back to my house without either us, or a extended family member knowing they were here... so it's not like they can see what they need and come back another night. When I'm at my station, it's a secured parking area.
So, I only have to worry about being parked while shopping and the like.. so locking lugs are a pretty good option for me.
Like everyone said.. the harder that you make it for them to steal.. the better off you will be. They don't want to work for the wheels.. they're lazy , otherwise they would get a freaking job and stop stealing from us working stiffs.. they're oportunitists .. and are looking for an easy oportunity to get something for nothing. Making them work, means they will likely just move on to an easier target.