viewing at different magnifications
Not clear what category this falls into.
Problems new to CC:
When zooming-in incrementally (command-spacebar, click), Illustrator frequently "jumps" straight to maximum magnification, forcing me to have to "zoom" back out to the desired magnification or even just to get my bearings and figure out where in the document I am.
This is very disorienting, and frustrating and bad for productivity.
Another issue, is that above a certain level of magnification, the object's center point vanishes, which is an issue if that's what you are trying to zoom-in on.
This seems mostly to happen in artwork mode.