I played a little of DIK. None of the characters hit any of my fetish buttons (and they're not particularly difficult buttons to hit: Big titty moms, big titty teachers, big titty older sisters, submissive personalities, bdsm). Milfy City has Celia and Linda, who while not perfect (they could both be much thiccer for my taste) I like both of them a lot. DIK's girls are all skinny barbie dolls with completely vanilla routes.
And the story... well, it's a consistent problem for me that I completely fail to connect with male characters on an emotional level. I don't care about your male MC, I don't care about his struggles, I don't care about his tragic backstory with his dead mom or whatever. If we must have a male MC, the best kind for me is a protagonist who's more or less an empty shell, with no real characterization or motivations, for me to inhabit and use to interact with the women characters. It's also much easier for me to slip into male characters on the younger/nerdier side as opposed to 20-something gymrat jock types. So the MC from Milfy City is more or less optimal, though I'd like a female protagonist even better.
DIK's protagonist absolutely does not want to be an empty shell, the writer wants him to be a fully fleshed out character, and I respect that. But it's a major obstacle to enjoying the game for me. And considering that there's nothing in this game worth pushing through that for... I dropped it before the first episode was over.
This is all personal taste, of course. My needs and priorities will be very different from anyone else's. Neither game is objectively superior here.