He is sweet, thoughtful, and seems to be very committed.
The question of maturity is often linked to the situation where an older woman is dating a younger man.
He could also choose to stay (and you could grow in similar ways and find more common ground) or leave for reasons completely unrelated to age. You have to make the best decision you can with the information and feelings you have at the time.
Given the focus on age, it's not strange at all that you have conflicted feelings.
While a man in his twenties or even thirties may still have quite a bit of maturing left to do a man in his fifties may not have this issue to deal with.
For this reason, it is not only the age difference but also the current ages of the partners that factors into the equation.