Mechanical heads are reliable though you need to have a well tuned bow and enough kinetic energy for them to work as effectively as a fixed/replacement blade head. Expandable heads are not a band-aid for a poorly tuned bow but they can help with a bow that produces so much arrow speed that it becomes extremely difficult to shoot fixed/replacement blade broadheads accuractely and consistantly even if the bow is well tuned. As far as how much kinetic energy is enough...that depends on the animal you plan on hunting. For whitetail deer most folks will agree that a setup generating at least 50-55 ft. lbs of kinetic energy is needed in order for the smaller expandable heads to function correctly. Larger cutting diameter expandables (1.5 inches or larger) need at least 60-65 ft. lbs of kinetic energy to get them to work well.

If I were to go suggest a company for good expandables then either Rocky Mountain or Rocket would get my vote. Both produce several heads that work well with the setups I listed above. As for fixed/replacement blade heads...yes, the Muzzy is definitely a good choice.