Mechanicals should not be a reason to not have your bow tuned. If your arrow is not flying straight and is fish tailing do not blame the mechanical broadhead for poor penetration. A poorly placed shot with either type of broadhead will have poor results. I put a 2 blade sniper broadhead through a buck at 55yds one fall and the exit and entrance wounds looked the same huge. I have shot fixed and mechanical heads and now a days they are both very good. As mentioned above the Rage heads are very goodand I would say stick to 2 blade models for better penetration. Before hunting with either type of broadhead fixed or mechanical make sure your bow is tuned properly. This will make for a much more accurate shot when the time comes.