Being a CS student I've had to take a course in basic software engineering. I was a little curious to find such elaborate "software development processes", like the spiral model, the waterfall model, et cetera. Some of these methodologies seem a little antiquated to me and, after speaking with several employed developers, I can't seem to find anyone who actually adheres to these models.

Does anyone here have experience working under the guidance of these models? Were they useful to you and your team during the development of your product? Or are these models just some way to communicate a sense of progression to interested parties outside of the development team?