I myself have used both (feathers and vanes) and prefer vanes. I found out when feathers get wet, they are weighed down, therefore not shooting straight when coming off your rest.
Also, how many times with feathers did you rub up against a tree, rock or bump the fletching of your arrow and find that several (blades) of the feather were distorted and/or missing?
I've killed many deer with vanes and I intend on using them instead of feathers.
Good luck and be safe.