Well, I loved my first AM Showcase. In fact, I loved it so much, I applied for a job. I taught part-time for years and I loved it so much, I quit my day-job (software developer with a degree in Computer Science and 9 years of experience) to work full-time at my studio.
Having been on both the student and the instructor side of AM Showcases and Freestyles and Dance-o-ramas, I love them. I sprained my ankle two weeks before our most recent one and it really upset me that I wasn't able to dance my students' routines with them. Our other teachers immediately learned the routines, practiced them with my students, the manager comped a couple of extra lessons, and everyone had a great Showcase.
So there's a lot of good. The only warning I would give you is to remind you that no performance is perfect - most students have a great time and love the event, but there are always some that can't get over some mistake or other they made in their routine(s). A fun routine always has challenging elements to it and mistakes are common...don't let it detract from the joy of dancing.