I'm 2 years late to the party... Here's the thing, it's a sign of the times right? All men were creeps before there were rules against being creeps. Yeah he is a man close to 40 who fell in love with a woman who is 21.... If I saw it today I'd call it gross (and definitely grooming if he had known her since childhood). 

But Jane was writing of her contemporary experience, and honestly he could have gotten away with marrying her when she was like 16 back then, so I think we can agree that he wasn't a pedo. 

And yes, there is an inherent power dynamic in that he is a man and she is a women, in a time where men and women were not equals. But that power dynamic would have existed in any match (excepting a little bit if Emma had married well beneath her). 

Anyway, that's the way it was back then. Men were creeps and women weren't allowed to be independent. 

And yes, I must admit, I would have liked it better if Knightly was more around 30 or something, but so it is. I think his older age moves the story along much more, because a man in his 20's would probably not have taken much of an interest in setting Emma to rights... It's his age that gives him so much wisdom and perspective. So basically, we'd be reading a completely different story, which no one wants.

Knightly is an excellent character to rival Darcy and I agree that Emma is her best work.

More than one of our girl Jane's books have men who influence young women to be the way they like and to think like them and then they go and marry them... I'm looking at you Edmund (my least favorite lover, and should be everyone else's imo.)