I had just upgraded from using blender version 2.75 to 2.77 and I immediately found a difference between the two. Here are the differences:
default perspective 2.75
default for 2.77
When I do a custom rotation using the same coordinates, the view becomes different.
In 2.77 it's no longer rotating directly along the z-axis.
How can I rotate the viewport on the z-axis in 2.77 as it was on 2.75 (or 2.76?)