Depends entirely on what you need. Generally, non-owned insurance (renter's insurance) just covers liability for hurting your passengers and whatever property you hit, and a small amount of hull coverage. The low amount of hull coverage is generally intended to cover the cost of the deductible for whatever insurance policy the owner has. However, it doesn't stop his insurance company from going back against you to recoup the amount. So, if the aircraft you rent has an insurance policy with a $5K deductible, you can just get hull coverage for that amount; but if you have an accident that does $20K worth of damage, theoretically they could come after you for the other $15K. How much risk/chance you want to take is up to you. I think all of the non-owned policies are about the same in coverage/cost, so AOPA is as good as anything else (at least within the same ballpark).
