Meh~ At least 90% of Hentai is disappointing to be honest. The best art is almost always ruined by some crazy shit like the aforementioned NTR, Rape, Mindbreak or stuff like Shotacon (How are these needles supposed to satisfy a grown woman? I just don't get it.). I'm also into mature women with mature bodies, but it feels like in 99% of the Hentais where such a women is the protagonist, you have the aforementioned bullshit. I really miss decent vanilla hentai with the kind of women I'm into. Mostly, it really devolves into hardcore rape nonsense. *sigh* I really wanna have vanilla hentai with all these awesome Taimanin girls or all these stunning (dark) elves.
Well, NTR almost always has a good art, because it tells a story, or raises social issues. Things like corruption, bribing, and employees not getting paid minimum wage. NTR is like a sad depressing movie
I've almost completely given up on het hentai because of the flood of hardcore shitty fetish shit. It's like for every 1 good vanilla het hentai i find, i have to dodge tens of shitty fetish hentai with shota, NTR or super insane ultra twisted fetishes (like some of those mentioned in this thread). I mostly stick to GL/yuri hentai because it's, to me at least, very hard to find trash fetish hentai (except exaggerated futa which is a plague on yuri hentai).
I read ntr doujins mostly because of the good art and i'd also most likely find other tags that i'm looking for there (ahegao,x-ray, heart pupils...). I never felt bad for the cuck guy since he usually sucks so bad that i think he kinda deserves it but usually i hate the stealers even more. The stealers are almost alway some deformed creeps, muscular thugs or delinquent playboys which i hate even more than cuck-kun or his dumb slut lover. The only type of ntr i found satisfying is netori when the adult-non shota male mc steal the girl away her toxic/unfulfilled relationship without using underhanded tactics (blackmail, hypnotism, rape, drugs...) but those are really rare.