Matthew and I talked to the reps at Aircraft Spruce Monday. Seems they say the only difference between the 396 and the model being released in Oshkosh, is the new model has a voice that talks to you. A talking GPS!
That's not quite true, there are a number of changes. I think the biggest one for me is the increased update rate. The terrain resolution might be nice, and the airspace changes, but they don't seem to be a big deal. Besides, the 396 already has voice prompting for terrain, towers, and traffic warnings (plus street navigation prompts).
