Sounds to me like the question you need to be asking is "what do I need to do to tune my bow to shoot my broadheads accurately?" Mechanicals should not be used as an easy way to get an out of tune bow shooting correctly. That being said both of the broadheads you mentioned are great and either one should be fine to hunt with.

My though on it being the arrows is if that were true then he wouldnt get good groups one day and scattered groups on another day. I going to stick with getting it paper tuned or use the walk back method but even with that method you will still need to paper tune. Go get it paper tuned and any good pro shop should have you shooting broadheads like a house fire in no time. Let us know how it works out for you. Keep an eye out as to how they do it and ask questions so you can do it yourself next time. Working on your own bow is the best way to learn the ins and outs of archery and with guyslike the guys on this site you should have no trouble learning to do so. Plus there are a few great book on the subject and TONS of info on the net.

Jason