Is there really any practical use for an all steel axe/tomahawk beyond “tactical” uses? Thinking something like an RMJ axe. I imagine that they can chop ok, but would not be as ergonomic as a wood handled axe and would transmit any vibrations into the user.
I’m not saying they are pointless, but their utility seems limited. Am I missing something?
They should have similar utility to a tomahawk, assuming you get one of the longer ones. It's not trying to be an axe though, at least not the kind I think you're comparing it to considering the ergo question. Tomahawks can have pretty uncomfortable handles because they're limited by the eye of the head due to being a slip-on style. I find the cold steel hawks very uncomfortable to use and prefer the one-piece hawks, at least compared to the cold steel. I still haven't tried a nicer options like a 2hawks.
I'm not sure the vibration transmission would be a lot different, wood handles can vibrate plenty as well. If you're using good technique, supposedly, you're supposed to almost throw the axe into the wood at the end of the chop so that you don't get the shock so much. by "throw" it's really more like loosening your grip a little so the handle can wiggle. Similar concept to a pinch grip with machetes.
I think the main advantage over a wood handle is better durability as you shouldn't be breaking too many handles, at least in the utility sense. For the more tactical sense, like breaching doors and what not, it's more obvious with the ability to pry. The main negative is weight since a wood handle of equal length is much lighter, assuming a hawk again which tend to have thinner handles. Maybe they can do a lot of milling underneath the scales to minimize this. That also affects the balance for chopping since you want a head heavy tool for chopping so the heavier handle is less ideal. But, they work fine.
I guess another subjective disadvantage is you loose the ability to remove the head to carry the tool in a more compact package, but that's certainly not everyone as most people are probably carrying hawks in a ready to use fashion.
I'm sure someone with more knowledge on hawks will correct me on parts of that but the one-piece hawks can still have plenty of utility to them.