287 to 87 to I-25 is a very good route
Agree completely. We always try to stay at the Raton Pass RV Park. It is a good place to begin the altitude transition. Easy on in to Colorado Springs from there.
The North bypass around Amarillo allows travel at normal speed. We have never had a slowdown.
Occasionally we will take FM 1061 which joins US 385 near the Cal Farley Boys Ranch. One year we attended the annual Rodeo at the Boys Ranch. It was great. Had a nice place to connect the fifth-wheel.
Usually we stick to the Dumas, Dalhart route because these are often rest stops for us--one or the other. Good Brahms in Dumas for a vanilla Malt!