This photo shows all three resolutions:
A very small section of each photo was used and the lower resolution photos were stretch to match the size of the higher resolution.
The image was captured using
http://IPAddress/Streaming/channels/1/picture
When running at 1920x1080 I ran into some intermittent behavior.
One camera went psychedelic which cleared when the camera was rebooted
The zoneminder moniter would skip seconds
Ghost images appeared when cars drove by
At 2048x1536 I got an image through zoneminder but the frame was frozen.
Simultenously using the camera interface the image was viewable.
I found using the video defaults in the camera gave the best stability (e.g., video quality set to medium).
The higher resolutions consume the limited storage much more quickly.
I went with the lower resolution.
If you have suggestions on tweaking the camera settings to improve these issue I would be curious.