Well Mr. Benton, I did. I rode JRC during Jan '83. Williamsfield to Montego Bay and return. Indeed an experience. I was staying in Mandeville (flew to MKJP/KIN, then rented - an experience in itself "in the Islands" - major brand matters not).
Next day, "the ride"; Williamsfield is about 5 miles from Mandeville, and I soon found the station. The station was staffed with a real live Agent-Telegrapher (I had left the MILW one year earlier - no such positions remained). He sold me a Round Trip First Class ticket to Montego Bay and return. The Westward showed up "more or less" on-time. The first Class car was a demotored Rolls Royce DMU. The Engineer's cab had become an Obs - at least Westward. The 2nd Class Coaches at that time were brand new Swiss manufactured. They still are rostered by the Cuban railways - operating or in what state of repair, I know not.
Nevertheless, the ride was scenic through the Blue Mountains and several tunnels. There was a twentysomething gal (her Father with JR) who said "you scream going through the tunnels". She was nice companionship for the journey.
At Montego Bay, there was no time and no use for sun, sand, and debauchery, I simply watched the engine being turned, talked with several "overworked" JR employees ("American Railroader", even if former, brought respect).
For the return, the "obs" was "on the head". Oh well, can't have everything. Now "on my own" for the return, I managed to alight one stop short at Kendal. OMG stranded at night, strange country, I knew it wasn't right as soon as the train started pulling. But the Conductor saw me waving and stopped. Who knows what would have been ahead; just would have walked on the tracks for the five miles or so to Williamsfield - and prayed.
I understand that passenger service was "done for" during October 1992 - for that matter, so was the entire JRC.
So that was my "one and only" on JRC. It appears that much of the Kingston-Montego Bay route has been chopped up. Apparently there was a passenger train revival of sorts Spanish Town-Maypen, but that was a "we gone, Mon" some one year after it started up.