The 3d view of airspace is very useful indeed for training. I remember I got a free copy of a book on planning flights with a magazine a couple of years back (can't find it now) which had a 3d view of a planned flight from, ISTR, Oxford to Bembridge or similar, which showed the airspace in 3d and made the obvious point that you could therefore fly OVER some of the airspace if you couldn't get clearance. Obvious, but it hadn't really clicked with me yet, as I'd learned to fly at Welshpool where CAS isn't a problem. I've tried Google Earth on one of my colleagues who is a newish NPPL and he found it very illuminating.
Tim