I, like many others in my neck of the woods, used hemlock as barn siding on a goat shelter some 25 years ago. As age set in, and the goats slowly evaporated, I decided to reuse the lumber for small coops/rabbit hutches, and not only was the lumber aged, but it was perfect for such applications... in some places was so hard it bent staples used for the wire bottoms! Yes, it can be hard on blades, but no worse than hedge-apple or black locust. The best part is any recessed grooves hold their integrity and do not expand/contract enough to split the fit. I also use a transparent cedar, oil based, stain to finish the structures, and they finish up beautifully! I have some that were sold/used for over twenty years, stained only twice, and are more gorgeous today than they were the day they were built... even exposed to KY blistering sun, torrential downpours, snow up the wazoo, and 15 below zero temperatures!
So use it, work it, thinking about water drainage while assembling, and this stuff wears like iron! I am truly a fan of hemlock and worked the family sawmill for 60 years, so I do have some experience with a lot of different lumber/s.