I personally found it pretty decent (though I didn't explore all the towns), though whether or not it is up to the same standard of Beth cities is probably quite subjective; I suggest checking out the screenshots and possibly some of the videos, as it does give a fairly good idea of what it is like.
It is aslo compatible with cutting room floor by Arthmoor, mentioned it http://www.nexusmods.com/skyrim/mods/47989/?tab=4&&navtag=http%3A%2F%2Fwww.nexusmods.com%2Fskyrim%2Fajax%2Fcomments%2F%3Fmod_id%3D47989%26page%3D1%26sort%3DDESC%26pid%3D0%26thread_id%3D1972144&pUp=1. The mentioned compatibility issues are due to a potential update for CRF adding a conflicting location, though I don't believe that has been done yet?
EDIT:
Actually, not the case. It probably does conflict with the very latest version, though you will need to try it out yourself and see how it goes; if it does, just grab an older version of CRF or skip Legendary Cities.