It's pretty much what you'd expect, one person having a lot more physical/emotional/mental experience than the other and being a little jaded, while the other has less experience but presumably more optimism and energy. She knew exactly what she was doing, and I could make her orgasm pretty much every single time - not because I was some sort of sexual stallion, but because knew exactly how to get herself off. My current 23 yr old gf, I can very rarely achieve it, and I think its a lot to do with her inexperience and insecurities.
It depends on whether or not the two of you can meet somewhere in the middle and make something wonderful of your time together while you can. There was the other pros of going out for nice dinners (she made around -0k) and doing stuff and having conversations about things that I'd never really do with a girl of my age.
Also being from slightly different generations meant that we had less in common and she would feel a little frustrated with that connection.
Obviously this is only one person's experience and others will vary, but this is all I could contribute.
When you are 50 and she is 30, will she still want to be with you?
Just keep in mind that there is almost a 20 year age difference, so while he's rockin' to Taylor Swift, you're humming The Commodores.
But, generation aside, if he shows interest then he's definitely digging your vibe.
Just because someone is in their 40's doesn't mean they stop finding women in their 20's attractive.
BTW if the genders were reversed, you can bet people would be calling her a cougar and joking about her robbing the cradle.