I would agree very impressive!
I have used those clip style hooks and they do work well.
One thing folks forget to share....... The hooks even with the spring on them can flip when you enter a run and lock you in the run. If even just the tip of the hook goes in the eye you can become trapped. I know the hard way. It was 45 minutes in the morning trapped inside since I did not have my cell phone on me before anyone realized I had not come back in. Yes there was loud laughter from my "rescuer". I use a hasp style on my run now as I have to actually lock my run and coop to keep thieving neighbors out.
The hooks with springs do keep racoons out.