Well yes, it's a painful scene. And really well scripted. For me, that whole Ashe arc, from when you go to her house to pick her up, to dinner, is the peak of the game so far. Then, after dinner, meh, there are moments here and there. If you just rape her, it's a scene without emotion. If you apologize, it's emotionally interesting, because obviously she tells you to go fuck yourself. A good scene. And if you drug her, and rape her while she's asleep, it's also interesting because the next day you have a completely broken and submissive Ashe.
Now, whether it's hot or not is very subjective. There are people who are turned on by that kind of suffering of others.
And well, beyond whether or not being a real son of a bitch turns you on, I recommend playing that arc in Dark Path at least once. It's really worth it as a dramatic story. And yes, I agree that Ashe's psychology (and Guy's too) in that arc is very well thought out. Which is funny, because up until that point, Ashe was a very flat and uninteresting character for me.