It took us about 4 1/2 hours from Denver to get there. You're kinda stuck in the middle so far as which route's quickest. Up through Steamboat & Craig to I-80 or over to Rifle & up would be your best bets.
So far as the worth it factor maybe some others could chime in with their thoughts. I saw another thread about the event as well. Here's the link to the website about the event.
I thought it was a good hole. Smaller boats excel in it. The good spot was surfers left but that may change. If you were willing to drive to Jackson for park and play, I think you'd be OK with Green River.