Well… I have all the trophies from the new DLC. Just went through it on Way of the Demon.
Mixed bag content wise imo… the free stuff everyone got with the patch is nice like the new Onmyo spells. Tonfa are fine I guess, though since they scale of the 3 stats I didn't raise at all I didn't use the much… just raised them to max Profiency and did the Dojo mission on WotD.
There are less missions this time around 2 main, 6 side, 1 Twilight, 1 Dojo mission. The 2 main missions and the Inari shrine side mission are fairly long, but the remaining side missions are pretty short imo. Bosses were OK, but as I said I'd rather have new Yokai bosses, there are too many Samurai battles already. Not sure about standard enemies either… bunch of new variations, but less actually new enemy types.
Didn't really start with Way of the Wise yet, except 1 mission to see what the Ethereal stuff is about, but doesn't look like there are any real surprises. Though you can get Divine Mariner clothes from the Prologue mission XD I also have to look at the new gear… some stuff looked interesting.
EDIT: finished the first region in WotW… this is fairly well done actually.
Enemies are reshuffled and old missions contain DLC enemies now, some Yokai have a new attacks (e.g. the large Skeletons can Axe spin now), there are at least 9 ethereal set bonuses for various build themes, though most people will stick to their old sets for quite some time (since Ethereal primarily drops from reds/bosses, I got an ethereal Yata mirror from a normal loot spot though)
Ethereal Set bonuses I've seen:
There are (at least) 9 sets
Susano - attack dmg
Amaterasu - Spirit/Ki stuff
Tsukoyomi - Onmyo
Futsunushi - PvP? (has Pierce Guard, 40% Iai Skill Dmg, Glory boost)
Shinatsuhiko - Wind
Oyamatsumi - Earth
Kagutsuchi - Fire
Owatatsumi - Water
pretty sure the other Elements exist as well
oh… and items that already have a set bonus, will keep that one and not gain any ethereal bonus