I've never found the panda rape scene funny but honestly I wasn't that grossed out by it either. It was a bit much but it was at least left to the imagination and presumably Homer wasn't actually raped; considering he was in the panda suit, it might as well have been a dog humping his leg. Well, not quite, but it would have been about the same level of involvement on his part.
In the end, they went a long way to drive home the point that Homer was sacrificing his dignity in order to make more money only to reclaim it at the end but it had its moments. The "Lenny gets something he shouldn't in his eye" gag has been done to death but back then it was still kind of fresh, I like the randomness of Burns being appalled at Homer throwing something at Carl but not Lenny or anyone else, silly as it may be. A bit much in places but otherwise alright. It tends to get lost in the shuffle for me, neither one I love or hate.