We are proud to have a student run team. We have one main mentor, who due to family obligations is unable to be there every day during the build season. In fact, I would say he is only there for about 15 days out of the build season. He handles all of the paperwork between to team and FIRST, which we are very grateful for, but he even says he enjoys watching us learn from each other and our mistakes rather than to do any work on the robot himself.
We also have Stanford mentors, but instead of giving us a lot of help during the build season, they run and offseason competition where we build mini robots for vex sized game, but with FRC parts so we give the freshman training. They rarely come during the build season, they are grad students though so they have bigger things to do.
I will say one thing though, if you plan on going with a student run and built team, do not expect to instantly be on the same level as those teams with engineers actively involved with the robot. I have heard rumors of our team being called "114 park" back in the day when we couldn't construct a reliable drive train and sat on the field most matches doing nothing. But these past 4 years have been in my mind a turning point for the team. Our technical knowledge has expanded greatly, mostly past down to us from previous years students. IMO our robots have become better and better, and being on the team for the past 4 years it has been amazing watching the team transform from a random group of students into a well organized robotics team. It may take time, but I find it rewarding knowing that a machine I spent 55 hours a week on is performing on almost the same level as that of professional engineers.
Just my $0.02, maybe more like $0.03
Mike C.