James,
Well done. Situational interviewing has been around for years and is still viewed as a technique which provides a thorough assessment of your candidates. Of course, your situational questions need to be based on a comprehensive job description as well, prepared in advance, and asked of all candidates. Doing so, provides a good basis for comparison of your candidates. The more you can learn up front in the interview, the better your chances are of hiring a candidate who is a good organizational fit and capable of handling the job responsibilities.
Pat