Really depends on the context for me. I mix and match head weights, profiles, and handle lengths dependent on what I'm doing so I don't have a strong preference other than within certain contexts. Crafting hatchets I like around 16" but otherwise I put hatchet sized heads on handles ranging from 18-22". I have a number of axes that in American terminology would be closest to "boy's axes" but don't quite fit neatly in that classification that I use for limbing, brushing, and scouting around in the woods that are on 18"-28" handles, and then full sized axes of various sorts on handles 28"-36". Some of those axes use slip-fit handles so I swap the handles out on the particular head depending on what I'm doing with it. For splitting I use a 5.5lb maul that uses such an eye and use it on a short 24" handle when splitting kindling but on a full sized handle for rounds. On hatchets I use heads ranging from a little over 3/4lb to about 1-1/2lbs, and boy's axes to full axes ranging from 1lb 2oz to about 4lb. I generally don't like going over 3lb unless the situation mandates it.