szap, One thing that you will have to take into consideration if you want to move to a helical is rest clearance. Could could actually create a bigger problem if you do not have proper clearance.
Personally, I use a GKF Premier drop away, so I don't have to worry about those problems. I use a two bladed cut on contact head and an aluminum arrow. My arrows with these blades fly the best with a lot of drag. I use a four fletched helical on my arrows, and it works great. They do slow the arrow down a bit, but that's OK by me. I'd rather have the best arrow flight and accuracy possible.