Good camera . . . but issue with video . . .

I have had this camera for about a year and a half, and consider it a good camera for the price. However, there are a couple of things that annoy me about it. The first one (relatively minor) is the clumsiness of the zoom. It is very imprecise - I often find myself going back and forth trying to find the right magnification - the zoom tend to overshoot the position I want.

The second annoyance is more significant. When recording video, when I zoom, the auto focus takes a long time to keep up with the magnification. While it is focusing, though, the sound gets quite low and muffled (I suspect this is due to the sound of the zoom being detected by the microphone, resulting in the sound gain control to reduce the recording volume, but I'm not sure). I am considering upgrading to the Z812 - due mostly to the ability to record 720P high definition video - but will not do it unless I'm sure what appears to be a design flaw is corrected.