In terms of your ball monitor - is it worth seeing what GC3 is like? It looks good from everything that has been put out so far, and is available in October.
I guess it will be good for instructors at that price though as from the MyGolfSpy article it's basically a GC Quad without some head data.
Since all the hardware is there and the features are turned off in software I wonder if we will see people hack these to enable all the features. I doubt it needs to be always online to work.