Edge enchancement shows up as exaggerated contrast, you can see it on gray to white or black to white transitions. In fact, heavy edge enhancement is easiest to see on a black to white transition, because it'll actually make a white line in the black box and a black line in the white box.

As for judging inherent sharpness, the first thing to do is turn the detail off. It's only truly possible on the JVC, the others don't go to "off" but you can get it extremely low on the Sony and Panasonic; you can't get it that low on the Canon.

Then you shoot the same scene and gauge which is actually resolving more, vs. which is using exaggerated contrast. If you could get both cameras "off" that's how you would judge inherent sharpness. You have to do the best you can by turning them both off or down as low as they'll go, and then if one is appearing edgy (like the Canon would because its minimum edge enhancement is stronger than the others) then you have to dial the other one up a bit until you get it to match.

vertical detail is a finer adjustment than overall detail, and it only affects detail between vertical lines. If you have a situation where you can easily see horizontal edge enhancement (like a white picket fence in front of green hedges) then you may not want to use the overall detail level, but may want to dial up the vertical. You can use both in combination; we're usually more sensitive to resolution increases (and thus contrast increases) in the vertical direction so v-detail gives you an option to fine-tune the image there. Note the original dvx100 didn't even have a v-detail option, it only allowed changing the overall detail level.

Look at the transitions from the black diagonal lines to the (presumably gray-ish) paper; when testing the three cameras at high detail levels I tried to equalize the "white halo" they all exhibited. Ideally you'd want there to be no halo at all if you're aiming to test pure raw resolution, but cranking up the detail lets you discern fine detail easier.

No, it goes from 0 to 15. 15 seems about equivalent to HVX +7, and "8" appears about equivalent to HVX +0, so 11 ~= +3 on the HVX. But the Sony gets extremely exorbitantly soft at the bottom end of the scale, artificially so. When Adam Wilt first demonstrated it we spent a while puzzling over exactly what in the world it was doing. I definitely recommend going no lower than 5 on the Sony.

Thanks Barry,
I'll let you know what we discover with the HVX.
I used to look at enhancement on a waveform by looking for little "flags" on the stairs of a chip chart, maybe i'll check that out as well.