Having replaced my internal gear cabling today, I can safely say that internally routed frames are stupid and I hate them all. First time I've changed the cables though so pretty pleased I did it and then managed to get the front and rear derailleurs working. I guess the test will be riding it tomorrow.
Also took apart the entire drivetrain and gave it a thorough clean, even taking the bottom bracket out and regreasing everything. The best degreaser I've found are spray cans. The Muc Off one is great.