What you noticed can be true. My Mustang has a wing loading of 14.6oz/sq' and it will turn with the best of them, probably tighter. I have been told by many people it "looks" like it weighs 55oz in the air. A lot of variables go into the turn, airframe design, CG, battery in relation to the CG, motor weight, prop dia, handle settings etc.....
I know a lot of people won't agree, but I believe heavier planes also out perform there light weight counterparts, within reason. Maybe not so much in calm air (that never happens anyway where I fly
), but in windy and turbulent conditions the penetration is better and will give a more locked on presentation (less bouncing and buffeting). Of course windy conditions can reach a point to where nothing will perform well or comfortably (03, 04 Nats!).
Both of these statements are my opinion from personal experience.
Mike