+1 on all of that. The most noticeable advantage is that there is virtually no play in the Callaham's arm.the precision of the Callaham is better (the countersinking of the screw mount holes), as is the production methods and materials. the Fender one is ok - this is one of those things where I'd really like to see a large number of people hear the difference. The Callaham has some advantages due to the materials and precision that help with tuning stability with vibrato use. And the virtual arms feel better to me since there is less play in the arm.
I always hated the wiggle, but if you like it I can't argue with that!I guess I'm the only one that likes the arm wiggle. Just reminds me of those old strats I've played as that's what they did. I know it's not better functionally, but what does it hurt? Still works great. That wiggle lets it hang real loose and swing out of the way nice and easy. I'm sure the Callaham is great, I just never had a problem with the Fender.