Reffing is VERY political at the college level. Basically they "use" younger kids under the guise of preparing them fpr Pro games, but that never happens. I've seen it happen to a lot of good refs in my area. I stick to D2/club when it comes to college as those games aren't under the radar like D1/D3 stuff.
I also do some juniors stuff, mostly a few showcases they have each year. Tier II/III midget, HS, and returning juniors players trying to impress college/juniors scouts. I've seen some amazing players over the past few years...