I just started agency PRN here, so far the agency staff has been lovely, it's all about the facility you go to. All agencies have a similar agenda/client list (seems that way).
So far my agency has been supportive, and always wants to make sure that I get fair assignments and not get treated like shite. I don't work very often and they are still super nice to me.
Hopefully it will stay this way.
I work as a travel nurse for Parallon, but I know several agency/local nurses who work for them. As a traveler I have been happy with them and I think their pay is pretty good. They have several HCA hospitals they serve in the DFW area.