Mine is rubber and it's just fine even after 15 years. Biggest issue is that falling limbs or running under a branch might tear a hole in it. All roof types have their needs for maintenance. Some people swear by fiberglass roofs, others swear at them. Look around all the vents, fans, skylights for places where the rubber may have been pulled away or damaged when someone was recaulking, inspect for places where the rubber may be torn, feel with your feet for spongy spots.
A well maintained rubber roof will last a very long time.