Claiming that sex if you're uncut is more pleasurable is speculation at best.
That claim may be wrong but it isn't speculation. Here is the testimony of one man:
Maybe Rick just had it done by a lousy doctor. I don't know. Anyway, my point is it should be the choice of the person having it done when they are old enough to make that choice.“I had ample sexual experience, and I was quite happy as an intact male,” says Rick Thomas, who was circumcised on advice of his doctor at age 26. “After my circumcision, that pleasure was utterly gone. On a scale of 10, the uncircumcised penis experiences pleasure of at least 11 or 12; the circumcised penis is lucky to get to 3. If men who were circumcised at birth knew the loss of pleasure they would experience, they would storm the hospitals and not permit their sons to undergo this.”