I recommend surveys to your members (they can be filled out anonymously) to get a pulse on what you're doing right and what you're fucking up.
There's schools of thought on whether to survey everyone or only your top 20%. I'm down with both versions.
Survey your top 20% of members - those who have been around the longest, spend the most, referr the most, create the awesomeness that is your community, make class enjoyable, etc.
It's not that the rest of your membership's opinion isn't valid - it's that most gym owners give into the "silent majority" when it comes to survey results.