I personally prefer Feathers, 3in with a right hellical. They may be a little harder to take care of, but I think the accuracy I get from them out weights that.
Both! I have 4" feathers and 2" Blazers as well as 2" Fusion vanes grouping together out to 60 yards as well as 3" Duravanes. These are with an offset. Why both, because I can LOL. Blazers for when it rains.