also, when shooting a fixed blade broadhead they will simple not track as good as a full length vane or feather. i believe this is a marketing gimick;
While I respect your opinion, I disagree. We've done extensive testing at the shop and they work equally as well as a 4" vane or feather, w/ the exception of big, heavy arrows. By heavy, I mean over 500gr.
I tested them as well. First, I shot a Magnus Stinger on my 425 gr. hunting arrow flying 285 fps into the deer target from 25 yards fletched w/ a 5" feather. Next, same set up only w/ Blazers. I shot a feather off of the first arrow. Believe me, they fly very well.