The first gymnast that comes to mind when thinking about this topic is Yelena Produnova. Produnova had amazing skills, and she was not rewarded for them at the time. On vault, she did a handspring double, which is usually a vault done by men. I have not heard of any other women doing this vault. Some commentators mentioned that this vault should be biomechanically impossible for a women. Apparently, the judges did not like it because it they feared for her safety.
I can see why this vault was not well liked. She consistently landed it in a squat, but if Produnova were doing this vault today, she would be well rewarded for doing this vault. Even if she fell over, she would beat a lot of DTY-ers.
Her floor was also pretty amazing.
Double arabian into a front tuck... then a layout into a double front. Those are two amazingly difficult passes! How many people do those now? Now, they would be rewarded for them. Not so much then. I know that Produnova was partly doing lots of forward tumbling to cope with an injury, but still, her skill-set is pretty much unmatched, even now.
The next gymnast I think of is Maloney. Maloney has been criticised for her lack of form and style, but could she ever tumble! Her passes included a double layout, a full twisting double layout and a whip to triple twist. Again, I think she would have done better had the current scoring system been in place when she was an elite.
I know that the open ended scoring system is not liked by everyone. When I see people chucking big bad skills, (cough, Nabieva, cough) I yearn for beautiful execution to come into play over difficulty.
But some good things have came out of the open-ended system. Bars has become much more spectacular. And if any people like Produnova and Maloney turn up, they will be recognised for their difficulty.
Yes, I am a bit of a Pollyanna with this, but the fact is that the old scoring system had problems too. That is why they changed it.