Provided your bow is tuned you shouldn' t have a problem with most fixed heads. Magnus, TH & Muzzy' s have always flown right with my FP' s. Wasp SST for what ever reason had good flight just a little low (about 1" on average)...but still a good head.

I prefer to use fixed heads and right now cut on impact heads. I just don' t want another variable in the mix and since flight problems are non issue than why should I change. The biggest thing I have against mech. heads is some use them to get away from tuning, but an improperly tuned bow will cause energy loss and can result in poor penetration. What ever head you choose make sure to tune it and you shouldn' t have a problem.