I've killed 16 deer with mechanical heads and 6 with fixed. I currently have both Slick Trick mags and Spitfires in my quiver. The Slick Trick mags fly great, but I'll likely use the Spitfires first. I've never killed a deer with a Spitfire and.... might as well make it 17 deer with mechanicals.[8D]
I used aluminum arrow for 2 years before switching to carbon. Now, I've been using carbon arrows for over 10 years, started with the pultruded shafts that had outserts. I'll never go back.
To each his own, but the notion that mechanicals should be illegal is faulty[:'(], I've got 16 successful whitetail kills using various mechanicals (mostly Rocket). Fixed heads can "fail" too. My wife hit a deer in the neck with this popular fixed 4 blade head.