I agree with Carolynn's response that academic medical centers are usually looking for CRCs. However, at my institution, the turnover seems to be about 2 years since most CRCs tend to either make the transition to industry where compensation is substantially higher or they pursue other advanced degrees; e.g. medical/nursing school.
I also agree that a CRCs workload is pretty intense since at some academic institutions CRCs seem to have a hand in everything from administrative to patient care. I've discovered that vacations are not easy to come by as you have to plan for coverage when you're out, and god forbid if the PI wants to start someone on a trial while you're out of the office or if one of your patients has an AE!
But becoming a CRC requires you to be a jack of all trades. You are exposed to every possible aspect in clinical research - regulatory, trial management, drug safety, data management, etc. This in itself can make you a very marketable candidate when exploring other clinical research professions.
Bottom line, it's definitely a foot in the door and it's part of paying your dues, but it can be rewarding with the right perspective and attitude. Sometimes you have to opt for the opportunity versus the pay to get the end result that you want. And don't forget, that as a CRC, you will be rubbing elbows with CRAs from industry who come out to monitor your site. This poses great networking opportunities and potential referrals if you produce quality work and have a great professional relationship with your monitor.