I would say neither is better or worse. It depends on what rocket you are talking about, and what you want the head to do. The Spitfires are sharper, and stronger, but they are slower to open. The rockets need their blades touched up before hunting, but they open quick. Some of the rocket mechanicals penetrate as well as fixed blade heads, while others have huge cutting diameters that cuase a lot of damage. If you give me the specs on your bow, either Kinetic energy levels or draw weight, arrow weight, speed ( if you know it) or type of bow and your draw length I can give you my opinions on what head I would choose with that setup.

TAKE YOUR KIDS HUNTING AND YOU WON'T BE HUNTING FOR YOUR KIDS