RE: 3 blade -vs- 4 blade
You won't notice a difference. I switched a few years ago from the 3 blade Muzzy to the magnum Tricks. They both performed well for me and very similar.
I shot several deer and antelope withbothand pretty anticlimactic following blood trails when you see the animal fall. I have yet to have to sort out a trail with either head.
I never had a problem with the Muzzy head and like the blade retention system. I didn't like the aluminum ferrule and that is why I switched.
One thing to consider is the total cutting surface area, IMO just as important as the diameter.