Exponent Engineering/Scientist - Senior/Manager interview questions

The people I met were very professional and enthusiastic. I enjoyed the individual meetings and "skills tests" - where I was questioned about product failures, why they happened and what a good solution might be. I had a good impression of the environment and found people to be honest about the nature of consulting, the challenges of racking up billable hours, etc. The one thing I found frustrating was the long, drawn out process. The interview process continued for several months without it being clear what my status was. I got the impression they were very interested in me but for whatever reason were unable to make an offer, but kept me "on the hook" for quite a while. My overall impression was very similar to the previous post where the person felt they were kept on the hook for months... I get the impression they want to keep tabs on top individuals so they can move on them as soon as a spot opens, but that they aren't actually looking to hire immediately regardless of what their employment webpage says.