If your plane comes in late in the afternoon or early evening better you stay near the airport and take a fresh run at anything Osaka in the morning.
the location of this hotel makes it so easy to get on the JR. It's the second stop from KIX right next to the station. Small yet clean room. I would think it would be better to take the train than to wait for the free shuttle bus at the airport. Just be sure to get the ICOCO card and the JR wide pass. Makes getting around easy. We got in really late because of the backup at customs (be prepared for a long wait) so the resturant closed before we got there thankfully a 7/11 is right next to the station a 2 min. walk.