If it’s honest feedback, that’s a good thing. Sharing feelings is also good when honest, unless the partner/relationship is just about mechanical sex.
I don’t at all find the following notions to be at all accurate or helpful, at least in my own experience and what I’ve heard of others:
* “turn him off because he wants challenge”
* “So he won’t like (If a girl tells you after sex that nobody has made them cum this fast before)”
As several others have said, comparisons are often a problem, and not just about sex.
And yeah, we don’t have much to go on here about who he is or what this relationship is about.
But I get a lot of intuitive red and yellow warning signals from the question and what is and isn’t said here.