For me personally, it was far and away my favorite long hike - though part of that was because I was pioneering something new and that's just what I really like to do.
For others though, I'd say the DHR is roughly on par with the CDT, scenery-wise (I haven't hiked the PCT, and the AT is such a different environment that it's unfair to compare them). The CDT has those "perfect ten" parts (Glacier, the Winds) that the RIB lacks, no two ways about it. I mean, the Sawtooths and the Wasatch north of SLC and the Paria are all great, but maybe don't quite rise to the level of jaw-droppingly awesome that you'll find on the CDT.
On the other hand, the scenery on the RIB is more consistently good than on the CDT. The CDT really does have quite a few boring filler miles (the majority of the state of New Mexico, for example), and while the RIB definitely has its not-so-great parts, I'd say an average day of scenery on the RIB is probably a bit better than on the CDT. I found that, because of this, the RIB was more rewarding on a day-in, day-out basis. Overall, the scenic difference between them is within whatever margin of error you want to allow for.
The major difference would be that the RIB is far rougher around the edges than the CDT is - more disappearing, crappy trail, fewer resources, more figuring it out on the ground, more solitude, etc. I see that as a feature, others may see it as a bug.