Comparing is harmful.
Comparing robs you of the opportunity to fully experience the moment.
When I compare one person to another, I choose which attributes I like about the other and revealing the lack of them as faults in another. They are different people. It is the same as saying I like apples more than oranges because apples are red. An orange is not suppose to be red. It has a different purpose.
When I say I like one vacation destination over another, I'm comparing two experiences that are not meant to be compared. What you can do is compare how happy you felt or how much you enjoyed each experience.
If you compare one friend to another friend, you hurt both friendships. If you compare your significant other to past relationships, you hurt your current relationship. Comparing people to people is not fair. They are different people with unique skills and quirks. Enjoy each person for their unique contribution to your life.
You can't compare past experiences to current experiences because your memory is not accurate. You remember what you want to remember. The best thing you can do is appreciate the current experience for what it is and learn from it. It is not better or worse than past experiences. It is what it is. Enjoy it.