As a freshman I walked on to a competitive division 1 team(top 10 at ncaas in xc within the last decade) with high school prs of 4:18 and 1:55. Ended up hating it. Transferred after one year to a d3 school with a quality coach which turned out to be one of the best decisions of my life.
Division 1 isn't for everyone, especially for the majority of walk-ons. What it really comes down to is coaching, and unless you are one of the stars on the team, the chances are that you will not be getting much attention. If you do decide to make the move to a d1 team make sure you visit the school and talk to some of the guys towards the bottom of the roster to really get a feel for what the coach is like. Also if you like racing I'd recommend staying in d3. Good luck with your decision, but wherever you end up make sure the coach genuinely cares about what's best for you.