RE: 4 or 5 inch vanes
PastorHunter:
I know that 4" vanes/feathers are common, but I do not know if they (4") can be considered standard.
5" used to be the recommended length for the best recovery, stability, and accuracy for broadhead mounted shafts. However, changes in broadheads, rests, etc, may make the necessity of a 5" unecessary for some shooters.
I would say, if a person uses 4" and his or her arrows fly good and consistently group well out to 30-40 yards, leave the setup be.
Having used both sizes, I found (personally) that 5" meets the criteria for me, and seemd to perform better in windy conditions.