I highly recommend this route... done it more times than I can count. It's quite possibly the shortest way and it's a beautiful drive all the way from Raton, NM to Boulder. You can spend the night in Amarillo if you don't want to Road Warrior straight through - we always do nowadays. It's at about the 10 hour mark on a 18ish hour drive. If you do go straight through, try to time it so you get to Raton when the sun is coming up so you can enjoy the scenery from there. I've gone the all-interstate route before and it's boring as hell. All TX, OK, KS and eastern Colorado. In other words... flat. The 287/I-25 way is boring through north TX (no way to avoid that) but then gets really scenic after that. Oh, and it's kitschy, but the Big Texan steak house in Amarillo is a convenient dinner and hotel for the night.
