You also might try the option under Options > "Rotate/Pan/Zoom options" > "Rotation style" (at the top of the dialog). Try setting Rotation style: Free rotation and see if that is better for you.

By default the rotation is "Rotate around world z axis" which does indeed constrain movement to keep the "up" direction along the world z axis which acts more like you're moving around a table observing things.

- Michael