I have a Pioneer Elite 151FD display and a Pioneer Elite 95FD blu ray player. Both are capable of 24p. When comparing the 24p output to the 60Hz output, the differences were subtle.
On another display, the differences might be more dramatic. The 151FD, and Pioneer Elite displays generally, have an excellent implementation of the 3:2 pulldown process, and so even at 60Hz, they look very "filmlike." On a display that executes the 3:2 pulldown process less well, the difference between 24p and 60Hz would probably be more perceptible.
So, the answer is: It depends on the display. Not especially helpful, I know. What it means is you must try both on the same display, if possible.
On another display, the differences might be more dramatic. The 151FD, and Pioneer Elite displays generally, have an excellent implementation of the 3:2 pulldown process, and so even at 60Hz, they look very "filmlike." On a display that executes the 3:2 pulldown process less well, the difference between 24p and 60Hz would probably be more perceptible.
So, the answer is: It depends on the display. Not especially helpful, I know. What it means is you must try both on the same display, if possible.