Truthfully, I play either, but I have a preference for realistic graphics, especially when it comes to the body proportions of lolis. Too many games give them strange body proportions, so I prefer games where they are more down to earth.
Realistic can look really good, but I feel like its harder to nail. Stylistic can look great in an endless variety of styles and I like the way exaggerated expressions look (big ahegao fan, no surprise). I'm cool with either though.
I prefer both for different moods. If I really want to get an immersive nut off then realistic. If I wanna have a little fun I like to go with stylized art because it leaves much more room for expression