Nah, the PS3 install/update stuff is the smooth part. They're obnoxiously huge and slow for GT6, but they work.
The real issue is with the stuff the game does internally. It can fall into a failed state that requires you delete the data and start from scratch (even redoing the stuff handled by the PS3's systems). Forced me to redo the entire six-hour process when I got the game recently.
Ah, gotcha. Wonder what sort of problems adding in the course maker might bring, lol.