If you want good, honest advice, just look at what the pros are using.

Logging is pretty big where I live. Whenever I look around, all I see are traditional axes with wooden handles. Good ash or hickory. The axes don't get used as much anymore because most of the heavy work is done with chain saws. But the folks working in the logging industry still need an axe now and then and they sure know how to keep it sharp and properly helved. I suppose there must be a good reason they don't use fiberglass.

Anyway, I think the average outdoor enthusiast really shouldn't dwell too long on the whole issue. Unless you do HEAVY chopping on a daily basis the extra durability of fiberglass just doesn't matter. A wooden handle on the other hand is easier to replace when necessary.

If your skills are so bad you keep smashing your axe handle into wood then you need to practice some more. If you can't hit what you're aiming at your axe becomes a liability and it's just a matter of time before you injure yourself.

So far I've only had to replace the handle on my axe once in well over 20 years. Dad and I have used that axe a fair bit, I dare say a good deal more than the average outdoor freak. The handle was damaged somewhat but I'm sure it could still go for a few years. Eventually I decided to replace the handle just to be on the safe side. Goes to show even plain old wood is totally up to the task.