I actually wouldn't mind something that could hit a 20 inch depth. Not so much to get down that far in the ground per se, but to make up for the 10-12 inches lost in tall grass, stubble, and other obstructions on some sites, but still yield 8-10 under the real surface.
And since we have stuff like USB connections and high capacity solid state removable memory/compact flash, I think it would be neat to be able to record the signals for a given find as it's being swept/scanned, downloaded, and then played back. That way, when we talk about 'how deep silver sounds' (or other favorite signal), real examples can be captured right in the field and shared, or reviewed again later. Or if the raw signals could be recorded and played back later, then maybe you could also play them back through after changing settings to see what the effect is (while not spending time on it in the field). How did that dime sound vs the Indian Head again? Just play it back from the wave file you captured real time. Yeah, the vids are great too, but that audio and number response info is golden to learn from.
