College students make great youth ministry volunteers.
College students are terrible youth ministry volunteers.
College students’ proximity in age to high school youth allows them to relate in ways older adults can’t.
College students’ proximity in age to high school youth renders their judgment and boundaries weak and makes them a liability.
Youth ministry is a terrific vehicle for developing the leadership capabilities of college students who may be discerning vocations in ministry.
Youth ministry is a vehicle for ministry with youth. College students need to have their own thing.
Okay, so I’ve never utilized youth ministry infrastructure to recruit and train college-aged young adults. I’ve worked with some as leaders, and those experiences have mostly been good. But I’ve never built a collegiate arm of a youth ministry program, even though I’ve always kind of wanted to.
Why would this not be a net asset?
YoRocko! 
As you know, this came about kind of organically for us this year. It seems to be working quite well. I have recently had more college-age students ask to join this group, and the ones that are already with the group have decided that they want to stay after for another 1/2 hour to have what we are calling “adult time.” My opinion so far is that the college-age advisors are learning how to work with flexible boundaries. I think it is a wonderful way to learn, and as long as this model continues to work for everyone I am really happy with the issues and resolutions that it brings to our attention.
I imagine that for the college students “Adult Time” with you is a big part of the draw.
What Krista said.