Forgive me if this question has already been posted elsewhere - I did have a quick look. However, I'd like to get a superzoom to help improve my bird/wildlife photography. The three main contenders seem to be the Nikon 200-500, the Sigma 150-600 Contemporary or the Tamron 150-600 G2. You can only tell so much from trying out in shop so I would be grateful for any experiences with any of these lenses. I like to print up to A3 and I won't be hand-holding very much if at all.