Do Jog Dials make for good UX?

This question follows on from my previous question. In one of my comments there I had mentioned that I was going to use a round slider instead of the linear one I had been using. Whilst this worked a treat on my touch screen notebook the performance on my test mobile devices was at best patchy.

Having gone back to the drawing board one of the ideas I am now considering is using a jog dial style control - such as this one. One of the principal benefits of Jog Dials is that they free you from the tyranny of 360° max imposed by a circular slider - effectively giving you a potential track length that is infinite.

This works - for instance, to allow users to select their age in the 0 - 99 range I use two turns of the dial. I have modified the control slightly to enable direct numeric input..

Whilst this works I have never run into anything like it in an Android app. I'd like to have a few views on how well this is likely to go down with people used to "typical" Android app UIs.

Even if it is acceptable one niggling concern remains this - in order to do a direct numeric edit the user has to click on the label displayed at the center of the control. Unless they happen to know this it isn't at all obvious that this can be done - though I could of course show a hint to that effect