I'm not too
concerned with arguing the case for default key strokes being setup.
So long as
it goes into the manual then people can set the keys up if they
wish.
I think
these functions can be very useful though. When using object navigation to find
elements that we know are on the screen somewhere but may not have a clear sense
of the object hierarchy it can be a lot easier if time consuming to just scroll
through all of the objects.
I have
certainly used this on occasion.
I've
assigned them to 3 and 9, prev and next respectively.