"In my thoughts and in my dreams, they're always in my mind
These songs of hobbits, dwarves and men, and elves
Come close your eyes, you can see them too..."
The only really good thing which could drop from Reach dungeons was Earthgore head... It was nerfed, so now - nothing really worth getting there. So far Dragon dungeons are better, in before nerfs to sets which drop there
Both of them are well-designed with interesting and fun mechanics. Dragon Bones has (imo) better looking rewards, but their HMs are insane compared to other dungeons’ HMs (the jump in difficulty between non-HM and HM is a lot bigger). I found the HotR dungeons generally more difficult in vet, but not in HM. HotR has Earthgore, a nice healer monster set, while DB has Zaan and Jorvuld, both of them nice.
"In my thoughts and in my dreams, they're always in my mind
These songs of hobbits, dwarves and men, and elves
Come close your eyes, you can see them too..."