I worked as a Sr CRC for a year and a half at a large, very well-respected hospital before applying to grad school. I enjoyed it in the sense that I liked it a lot more than what I had been doing before, and I loved research. I liked people around researchers and people in academia. I hated it in the sense that the majority of the doctors/fellows I was working with did not respect me, except for my boss. I had tons of crap jobs to do that were pointless, frustrating, and time-consuming. I essentially learned how to be resourceful and how to edit manuscripts for people who did not speak English. :-D By the end of the year and a half, I think I was crying in the bathroom about once a week on average. It was exhausting, and at times demeaning and frustrating. But it is somewhat of a rite of passage, and in reality, I did learn a lot. That being said... a year and a half was sufficient.
There was someone at my workplace who made a career out of it, but she moved into a managerial role. She also had to put up with a lot of BS, and I'm sure she had her share of crying in the bathroom, although she never really showed it. :-D