I've done the Rockies a couple/three times. Truly spectacular. A few years back I took a trip from east Kansas through Yellowstone, on to Boise to visit relatives, then south through Salt Lake City to I-70/Green River UT and on home via Denver. That was my first time riding in the desert and I fell in love with it. The road from SLC to Green River UT (HW 6) was fantastic. I discovered the spot where they filmed a lot of the Road Runner/Coyote cartoons. Found a cliff that still had an anvil shaped hole at the bottom.
Spent a couple weeks on another trip and meandered from Sacramento CA via HW6 to the Moab UT area. My first time in that area on the bike or in a cage. Breathtaking scenery. I especially enjoyed HW 128 that goes northeast out of Moab up to I-70.
I think I like the desert over the mountains because of what I call "Scenery Overload." In the mountains the scenery changes so fast that I find myself unable to absorb it all. Mountain view...water fall...tall trees...another mountain view...all in a few seconds sometimes. In the desert I get to see the various geographical features for 10-15 minutes or longer as they get closer and closer. But that's just me...
There are a few of my favorites photos from the trips I mentioned in my photo albums.
What a lot of people don't know (including me until I moved here ) Colorado is considered high desert. Once you get out of the asphalt jungle along the front range on a windy day your dodging tumble weed. I have the best of both worlds, mountains and high desert.