That is a good question. Having worked with one as a nurse manager I can see where I could have my doubts, but I've got to say that there is good and bad things to know about them. First of all, they are similar to military recruiters in that they serve the function of filling up the open positions. So, they are, to some extent, salespersons. They are going to put their hospital into the best possible light because they are trying to sell you on their product, their hospital. However, if anyone knows what the nursing staff needs of the hospital are, it is them. If they've been in their job for awhile they will know the unit managers and what they are looking for and they are aware of the number of open positions. They also know what is available to new grads--not all managers, particularly newer ones, will know that. Recruiters usually know who the other recruiters are in town and what they are looking for in nurses. They also know the local nursing schools and instructors working there. I think you're safer if you are working with a nurse recruiter who is also an RN, rather than someone in human resources who is designed the nurse recruiter just because they hire the nurses. An RN recruiter is going to understand a nurses needs moreso than a non-nurse. Recruiters can also be a great source of information. They keep up to date on the salary scales paid by the various hospitals and that is no easy feat as many hospitals guard this information as a corporate secret from other hospitals. They will, generally, know where the nursing fairs are, as well.
As you look for a job I would just caution you to be a little aware that something that sounds too good, just may be a bit of a stretch of imagination. Also, you've probably read enough on the forums about cranky older nurses who can make the life of a new grad miserable. There is no way to predict where those cockroaches are going to pop up. A nurse recruiter and even a nurse manager isn't always aware of the existence of those kind of people. It is very helpful if you can find nurses who work at various hospitals so you can pump them for information. This is why I think it's good to go to continuing education programs outside of hospitals since you get to meet nurses from all over town. But, again, be aware that when you are talking to employees, their perception of the places they work is based on their own experiences. You might be talking with a perfect employee or with someone who has a negative attitude about a lot of things in their life. Each will have a very different viewpoint to tell of the same hospital.
Guess what I'm saying is that it's a crapshoot. There are some things, like new grad orientation programs, however, that they are truthful about. I would suggest that if you are concerned about getting stabbed in the back to have a backup Plan B and Plan C. Detail in your mind just what you are going to be willing to put up with at a job and where you are going to draw the line and then follow through on it. I've written before about two instances over my career where I was lied to about the terms of my employment. I left both jobs within a couple of weeks once I learned what had happened and got no satisfactory resolution or response to the situation. The first time it was my very first acute hospital job out of nursing school. The second time it was about 25 years later when I was more experienced. I never saw it coming either time and I don't consider myself to be a dummy.