Interesting.
HR Kyoto is by far the better of the two. Kyoto is by far the 'better' city as well, at least from the average-tourist point of view.
If you don't intend to leave the hotel, at all, then the HR Osaka actually has an advantage because it has a lounge (nothing to write about), it has very good offerings during Happy Hour and it's closer to the airport (still a long drive though).
But HR Kyoto is a much nicer property with great rooms, excellent breakfast and excellent restaurants on site and it has a spa.
I'd take HR Kyoto. Do make the time to visit the city - it's a gem.