With the quality of most carbon arrows, you may have a darn difficult time getting fixed blade heads to shoot straight. You' ll likely find only a few arrows out of a dozen that will consistently shoot fixed blades, and that' s with the premium shafts. You won' t find that many with the low end stuff. I think that' s the main reason mechanicals have gotten so popular.
Mahly 13 is right. Most of us ' old guys' (I prefer to think of us as ' experience enhanced hunters'

) frown on mechanicals. I know mechanicals work, when they are checked out to make sure they function properly and the blades are sharp, and the arrows are tuned right and when the bow is tuned to shoot accurately, and the shooter uses that accuracy to put the arrow where it should be. But after 45 years of bowhunting, I know that just because something SHOULD work doesn' t mean it always WILL work in the woods. Stuff happens.
You have to do the same things as far as sharp blades, tuning and proper shot placement with fixed blades, but there isn' t any worry about whether they will function properly. When the blades are always open, you know they will be open when they' re going through the animal.
But if you go mechanical... First and foremost, make sure you' re shooting enough bow. Most mechanical broadhead manufacturers recommend a minimum of 50-55 ft lbs of energy. Take time to be absolutely sure the things work. Most of the mechs I' ve bought to test have not been good, even top name brands with good reputations. The blades would not open on their own and some wouldn' t open even pulling on them with pliers. I had to remove the blades, clean them out and remove burrs from the pivot holes in the blades before they' d open up. That also means they can get dirty and sieze up again. So check them out before hitting the woods. EVERY time.
Otherwise, you could be here at some point during the season with yet another story of ' mechanical broadhead failure.'