Well I guess it's completely up to you. I've been using hammers since the beginning, but now (lvl.48) I'm using a frail (or a mace :/) because of the good stats...Attack rate is faster, but it does seem to give less damage. But I guess it depends on how much you miss the hits. If you don't miss much, then I guess the damage you will give to a mob would be about the same in total...(If you don't really get what I explained here, I could explain further using simple numbers ^^)
So...my comment is....get whatever you can get :P Why waste time trying to get a particular weapon when you could easily get an as good one?
Green weapons are pretty good at lvl40's I guess..But I may be wrong XD