I play in a group where we routinely switch out GMs. When I GM I tend to prefer story-based games with lots of character building and descriptive role play. We tend to run Paizo's Adventure Paths just because we all have jobs and families and lives and such and doing so cuts down on the prep work, but when I'm running a game I still tend to put a lot of work into fleshing out the modules.
My challenge has been that things seem to start off well, everybodies into role playing and we're all having a good time, but after a few sessions (typically 3-4 hours on a weekday night) my players seem to get bored with things. It feels as though they want to get on with things, to level their characters faster, to move through the modules quickly and to "get it over with, so we can go on to the next thing." We've started and stopped several APs this way, and we're lucky to make it 4,5 levels before the "go go go" mentally eventually leads to a TPK.
Any suggestions? I'm quick to blame a MMO mentality here, but all of the players, including myself played pencil and paper long before the advent of online gaming.