While I can't go at it every 20 minutes on a whim now, I can say that the sex I have now is far better than the sex I had then.
Both for me, and my partner. Honestly the sex I have now with my wife is the best sex I've ever had, and it generally continues to get better over time.
But, I actually work at getting better over time.
As for attraction, there's a basic level of maturity I'm not willing to go below, and generally that comes with a specific age range. While I may find a 23 year-old cute, I'm not likely to consider her as a fully matured person who has a good grasp of who she is yet. Generally 25 would be my cutoff at this point. Really about 8 years either direction for me is my limits. And I find women ~ my age generally more attractive than older/younger.
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."