I have actually never attended a showcase run by them, but do intend to do so this winter and definitely a few next year (I'm an '08). However, I have attended several tournament events run by them. PG is excellent at what they do, and really work to provide the best possible exposure for the kids. While some events have much greater competition and scout attendance than others, every event they run is of high quality. If you can do it, attend them.
Let me know if you have any more questions. There are tons of helpful people on this site and some that know plenty more than I do, so feel free to ask away