We went to Bryce and Zion this past Fall, and it was just breathtaking. Didn't ride the bike (my 86 fxrs), but took our Toyota Spyder convertible. Saw lots of bikes, though, and had a pang or two.
Bryce was more "unworldly" with its Hoodoos, but we both preferred Zion for sheer beauty
We want to go back on the RG, maybe next year.