the 2012 has the oil leak issue. You may want to search about it and understand how it would affect the car.
the 2011 has no such issue, but you would loose out on the changes that the 2012 car has (better FC, lower seating position for the rear, and narrower bar across the rear windshield).
I would highly recommend to find high and low for a car which has the service booklet at hand so that you the car would stand a better chance to be eligible for the hybrid warranty (8 years, unlimited mileage). Then check with Honda SC if the car is still eligible under warranty. It would at least give you some peace of mind in case something does go wrong. Do note that for 2011 model the warranty would end this year, and for the 2012 it would run until next year.
While test driving it, try to drive on a flat stretch of road and engage the battery only driving. You do this by lifting off the throttle and really gently pressing the throttle. You would feel the torque is slightly stronger compared to when you are driving it from the engine power. In the driving mode, maintain a steady speed, and take note of how long it would take for the car to fully discharge the battery. Try it a couple of times at the same speed and the discharge time shouldn't differ so much.
Apart from that, the regular checks of buying a used car still applies

Good luck
Alright note. Helps me alot thanks