RE: 4" or 5" vanes - Pros and Cons ?
I would say that a lot has to do with what type of shooting you will be doing. It you are going to be using field tips mostly, then I would say either would work fine. If you are going to use fixed bladed broadheads with these arrows, then I would lean toward the five inch.
The five inch will produce a bit more drag on the arrow, making it a bit more stable, but also a bit slower.
On my hunting arrows tipped with cut on contact broadheads, I prefer using four five inch fletchings helical.