I have the HF crimper as well.
I bought it for making cables for the inverter and batteries in the camper. Seems to work fine. The wire sizes marked on the dies seems to be off. I just took a lug and wire and used what looked to be the right size die. It worked fine. Nice crimps every time.
I could have borrowed a crimper from an electrical wholesaler, but I wanted a nice hex crimp, not the push pin type crimp.
I think the only way one would wear out the dies is if one were doing a lot of crimps, as in an electrical contractor crimping service lugs on multiple jobs.
To check the dies, look at them. There should not be a lot of discolouration around the crimping surface, and there should be no nicks in the crimp area.
I won't get into the solder/ no solder debate, but in the electrical construction and maintenance fields, only time I used solder was for small wires and electronic connections, where there wouldn't be heat generated through the connection.
As far as renting, I doubt you will find anything for rent at the price of purchasing a HF crimper.
Brian
