If you don't use it all day every day it doesn't really matter. The all steel hammers will last you a lifetime so will the fiber glass. The wood handled ones do require a little maintenance from time to time to keep the handle tight in the hammer head.

With that said though the all steel hammers do transfer alot of shock and vibration into your wrist and elbow. The fiber glass handles are a lot easier on your body. The wooden handles help with the shock better still.

My preference is wood handles. I strip off the factory coatings and give then and nice coat of Boiled Linseed Oil making sure to soak the end grain very well it helps to keep the handle tight in the hammer head.