You can go to a trajectory table to find the speed for the Helical vs. Offset; you will see that the Helical kills speed faster. But you will use, that which is necessary, to give you the accuracy you wish for, in the way that you have your Bow set-up.

Crashman:
Thanks for the info! Real world tests are always more eye-opening than claims made by manufacturers.

dwaasp:
I think you hit the nail on the head. What works for you is what you should stick with. Where I hunt, anything over 25 yards is bound to be through some sort of obstruction and therefore, I won't take them. I'm currently shooting a medium offset and am liking what they do to my arrow flight. Speed is of little importance for me since I'm of the mindset that it ranks near the bottom of the importance factors as far as successful hunting. I'm hoping to get a fletching jig and try a mild helical at some point after the season.

Hear's a silly question, why right and/or left helical?

I prefer right helical because I like my arrows spinning to the right. Left helical vanes cause the arrow to spin left which could unscrew the tip. It doesn't matter since my tips come unscrewed anyway.[:-]