If you want to switch to a mechanical head of any type make sure it is for the right reasons. Wider cutting surface, better blood trails, and maybe to feel better not having exposed blades while in your stand, ect...
Mechs. are not a bandaid for a poor flying setup and even though they may group well, they will suffer the same penitration problems as a fixed broadhead if the arrow is whipping in flight. Make sure your bow is tuned before switching and also follow recomended K.E. for the head you use. There has been a lot of good info here on finding kinetic energy if you do a search.
With proper K.E. and a well tuned bow, the spitfires are a very good head. (but not my first choice in mechs.)