Dr. Ashby addresses this completely in his writings. Broadheads w/o vents do not run the risk of this potential drawback and there are plenty of them out there to choose from. I have shot thru animals with and without vents. I have also had excellent results with the 190 Ribtec, which as you know, has the stamped/vented ferrule which "should" create even more drag/resistence than a vented blade(subjective).
My personal preference is to use non-vented BH's
as I believe they fly quieter, may be stronger and have less potential to "hang up".
Having said this, I would still use a vented head if it appealed to me!
Kris