Okay, I know there have been similar discussions on this. But this isn't a " when do you change heads" thread exactly. My question is this: Should I change my heads preemptively even though they appear fine? Perhaps a little background here. My drumset is 3 years old. We practice about once a week and gig around 10-15 times a year. I have all the same heads, except snare and bass. While I love the durability these heads have afforded me, I am a bit concerned that they are getting "bad", even though they appear good. Do you guys change out your heads BEFORE they actually tear? Should I?