From Houston - hoping to avoid Dallas - I'd go 290/190/6 through College Station to Waco - continue on 6 through Meridian to Hico - pick up 281 and north to 287 in Wichita Falls - then to Amarillo. Up to Dumas and over to Raton, NM. Then north on 25.
Or you can get off I-45 onto 287 at Ennis, go through Fort Worth and out 287 to Wichita Falls.
I find 281, 287, 190, 6 all to be good roads without too many slowdowns, smooth and easy to drive.
I-35 North from Dallas to Oklahoma City is okay. And to the Kansas border. The interstate is a toll road up to Wichita - cheap and worth the cost. Haven't driven the rest of the route to CO recently.