I had some great pics when I was put near the front last time. An ostrich walked right up to the front of the truck and had a stare down at the driver who was laughing. She said she'd never had that happen before.
So it just varies depending on what's going on with the animals.
I've found that the back row makes for an exceptionally bumpy ride for us, so i avoid that. And I also to avoid the first couple rows because the driver's enclosure blocks part of the view. The CMs have always been accommodating if I ask politely for a different row than the one they wanted to put us in.
The back rows are quite a bit more bumpy that the front rows. With my back issues, we always ask for more front row seating. As for left and right, over the many times we have ridden, I find it about qual for each side overall.