ORS and GGGB are visual novels. So of course the art and the writing are going to be the most important aspects. The art is obviously better in ORS, I don't think many people would contest that. Writing wise it's more subjective. GGGB had more focus on fetish elements, corruption, and darker themes. Those were it's positives, it's negatives were mainly with its reliance on stereotypes and one dimensional characters. ORS isn't as heavy on the dark elements, but uses a lot of the same stereotypes as GGGB, but builds upon them with more characterization.
Tyrone is the BBC fetish stereotype? Jerome is too, but is also the friend of Ian, a guy with little backbone that leads to him messing with Louise and potentially pursuing the girl his friend has an eye on. Jack is the chad stereotype? So is Axel, but he is insecure, manipulative, the ex of one of the MCs, and a minor antagonist to the other MC. You get the point how ORS builds upon GGGBs stereotyped characters.
The last thing where the writing is different is the inclusion of Ian. He is not only a love interest for the female MC, but also an MC himself. EKs patrons don't seem to be fans of him as much as they are of Lena. Personally I prefer ORS, I like the characters more, the art more, and I don't notice any dip in quality for the writing during sex scenes. I also prefer Ian over Lena, so that might play a role into it and make me biased in a certain direction.