Although we did not see Caher castle so cannot compare the two, I would highly recommend seeing the Rock of Cashel with the guided tour, which previous posters did not do. Our guide was extremely knowledgeable and thus we had a great experience. The cathedral ruins, and especially the cemetery are about as picturesque as we saw during our entire trip.

We really looked forward to seeing the Rock. While it was impressive, it somehow didn't stun us like we had hoped. May not help that it was freezing cold with a strong wind and hail pelting us. It's just a great ruin. And the video was indeed too generic. If you're near Cashel, it's definitely worth a trip. But it's not worth a special trip. Caher castle did look more impressive to me.

While the views and the history of the Rock of Cashel are great, I really wasn't as keen on it as I expected. It's definitely worth a couple hours if it is on your way to somewhere or near where you are staying but don't make a special side trip just to see it. I was surprised actually of the size, i expected something bigger. The video presentation I had hoped was going to tell something of the history of the building, but instead it was just basically a brief synapses of the religion and area. St Cormac's cathedral is fascinating though and the paintings in it may not last much longer. Like another reviewer said, there are plenty of free or less pricey (not that the ROC is expensive) places that you can explore. I would recommend the Cahir Castle over ROC any day.

We totally loved this place. The details that were carved and are still there were impressive! Don't miss this!