I work for both systems with their staffing agencies. I don't have too much bad to say about either of them, however you should follow what you love. It is much easier to do what you want the first time. Learn from my mistake, I switched to Med/Surg to do agency to get paid more and have more flexibility. It's ok, but my passion is oncology. I don't hate going to work but it's not the same as it was when I was working on an all oncology floor.