In my area, Hackberry is a cousin of Elm, known for splitting hard, but not as bad as elm. We have plenty of cold weather, so most hand splitters will wait for cold weather...or burn elm and hackberry in an outdoor boiler, where if you can wrestle it into the stove you can get by without splitting! If you split with a hydraulic splitter, it really doesn't matter.
It is a little lighter and less dense than oak, birch and maple, for example, and doesn't seem to make as good coals, but is about as good as ash, and better by far than basswood, popple (aspen) and willow.
The smoke doesn't smell very nice, and in my area the wood seems supsceptible to a fungus disease that causes dry rot in the pile...it stinks even worse then. If you use it up within a year or so that won't be a problem