I've never flown BA Y (long-haul), but NZ PE (747, 777 has narrower seats) easily blows BA PE out of the water. I did fly NZ Y a few years ago, and was impressed by both the legroom and service. The cabin interior has been renewed since then, but I think the legroom is still much better than BA Y.

In J I'd be happy with either. BA has a slight preference perhaps due to the ability to look out of the window easily, and I do prefer the seat. Due to the interesting NZ (VS) design the seat doesn't recline far enough in seat mode IMHO.