Hi,
yes, it took about 45 mins on a deserted highway at 1pm on Labor day weekend.A very smooth ride into Boulder with about 5 stops to pay tolls ranging from $1.75 to 75c.
I would definately take the drive rather than stay at the airport,
just remember the directions for the hotel you are staying at, nothing worse than spending an hour looking for your hotel in the dark !
Angie

I ride that road quite a bit... it gets no traffic. So you can pretty much always assume it will be deserted.