Recently installed one of these inside a warehouse covering ~20 overhead trailer doors. I have to say I was very impressed with the coverage and image quality. Made me re-think my thoughts on wide area camera's, I have never used one that produced a satisfactory image. I did have one interesting issue when using the Axis VMD application on all three image streams it seemed to overload the camera processor and live viewing was very sluggish. Took me a while to figure this out and re-installing the application and re-applying settings got things working well again.
Because of the reasons in my reply to #1 above, the edges of FOVs aren't matched up. The Axis is shifted more to the right, and captures part of the red car in front of the Explorer there. Vivotek captures more of the building on the left. Also they are mounted on different tripods, and there's about 4' of space between them, so the angle differs due to that, as well.
It may be slightly off level. It's also aimed slightly differently. Because the Axis uses 3 imagers, you can center the target in the middle of the FOV. But if you do that with a 4 imager camera, they will be directly on a seam between two imagers.
So the Vivotek (and others) are skewed to the right/left so we can get a clear shot of the subject/chart. That makes it look less level than it is.
I am curious about the mounting height of the 180 cameras in your test. I have a contractor trying to tell me mounting them at 25' and trying to view the walkway below is best practice. I see pedestrians feet from the middle sensor and mostly blue sky from the right and left sensors.