To be honest, if a game is good enough, you should be enjoying it without even caring about progression.
I have tended to find that if I start wondering about progressing to the next level, its probably because there is nothing worthwhile left in the game for me.
On the whole, I'm not a fan of XP-reward levelling, even though everyone uses it. I would prefer character development and progression to be based on in-world activity and choices, but that seems to be beyond the horizon for most designers.
