I actually did Kyoto-Narita by train and while it did consume a fair amount of my day, it wasn't unpleasant.

My train left Kyoto at about 11:30, and I transfered to the Narita Express at Shinagawa in more than enough time to catch a train to NRT at about 2:20. I could have actually taken a later train from Kyoto since the connection at Shinagawa took all of about 5 minutes. I arrived at NRT at 3:30 for a 6:30 departure, which was at least an hour earlier than I needed to be there.

So, in reality the trip from Kyoto could have begun at 1:00pm leaving me time to catch the 3:30 NEX at Shinagawa and still giving me 2 hours at NRT.

The trip was very comfortable and I got a lot of reading done - and saw Mt. Fuji on a rare clear day.

I allowed such long transfer times since I was unfamiliar with the stations and I wanted to allow for late trains. In reality the transfer was easy, and Japanese trains run to the second.

I think I left Kyoto at about the same time (or later) than if I had taken the tain to KIX and then a flight to NRT.

Of course, direct to the states from KIX would be easier, but in my case the prices WERE quite different (availabiltiy, I'm guessing) and I got a sweet deal on a D fare on SQ NRT/LAX.