American Express Membership Rewards points have historically transferred to Hilton at a rate of 1000 -> 1500. So 1 Amex point was worth 1.5 Hilton points.
That’s not a rate I’d want to transfer at. I value Hilton points at 4/10ths of a cent and Amex points at 1.8 cents apiece. Sometimes they’d run bonuses where 1 Amex point would yield 2 Hilton, still not a great deal but better of course.