I'm wondering what a day trip from Negril to 9-Mile is like. I know one person's grueling is another person's "no biggie," so as an example, we've done the Playa del Carmen to Chichen Itza tour in one day (2.5 hours each way plus 2-3 hours at the site) and while we were tired, we felt it was do-able and totally worth it.
Still pondering whether or not I want to miss a day on the beach to do it, but travelwise, how is it?