I have AWWX on my ipaq 5550, which is the predecessor to the 4700. It
works fine - updates are not instantaneous, but there's no need to be.
I've recently worked through a XM activation problem, but it appears to
be fixed now. The GPS has always been trouble free, and the IFR page
shows airways with MEAs, which my Garmin 430 does not.

I looked at the Raven large screen display at Oshkosh and decided that
it was just too large and heavy to try to put within convenient reach.
I mount the IPAQ on a suction mount attached to the lower left
windscreen so it's only about 15 inches from my eyes. If you need to
work with it, you can just remove it from the mount and it maintains
GPS contact on batteries until you put it back on the mount.