We moved in Highlands Ranch, from Richardson TX (Plano schools) 2 weeks ago! :-) So far, we love it here!
We went for Douglas County Schools. They seemed to us like they were pretty close to the quality of the PISD schools. Compare to traffic in the Dallas area here it's a lot easier. It might not be as bad as you think to live in Highlands Ranch and work in Denver. But, it's really up to each person...
Besides the schools, we like the fact that we have access to 4 rec centers, each with a pool. There are lots of parks, greenbelts. And tons of kids around! We have an 8 year old boy with no siblings so kids in the neighborhood are very important for us.
Good luck with your move! I'm sure you'll love it here.