A couple notes:
- On the cable length thing, the 6' minimum length came up in discussion at the Lumagen forums. I haven't read it in depth enough to talk about it, but you can seek out the details here at AVS, or over at the Lumagen forums. Considering the handshake issues I have with my Marantz sometimes, I might swap in a couple more 6' cables and see if it makes a difference (same brand as what I currently use, to keep it the same)
- A different cable won't offer blacker-blacks or whiter-whites no more than a different Ethernet cable for my PC will offer sharper fonts on the emails I send. With all the encoding that happens to the signal on send and receive those things just don't happen.
- I see no point to offering a screenshot of anything. That's introducing a whole new level of variables with the camera, how the image was processed, and everything else. I'm trying to write something for the QD882 that lets me do a direct frame capture from players, and Stacey Spears has said I can use images from their discs for this if I would like, which can then show the processing effects. While screenshots of projector setups and such look nice sometimes, I don't think they offer any realistic version of what you are seeing with all the variables that come into play.
When someone mentioned that they showed their friends the enhanced and unenhanced versions back-to-back and they went for the enhanced ones, I wasn't surprised. We adapt very quickly to what the eye sees, and so if I change my TV from being calibrated to vivid and then back, the calibrated one will suddenly look dull and washed out. Before vivid was turned on it looked great, and 15 minutes later it'll be great again, but my eye has then adapted to that quick rush of color. It's why calibrators have to use instruments and not go by eye, since we adapt far too easily to visual changes and can't get a neutral grayscale by eye, or colors by eye, past a certain point.
The best ways to show the benefits of an accurate image are choosing material that will show the flaws of lacking one (say Art of Flight, where you will have totally clipped highlights while they snowboard, and you can easily see the mountains go from detailed to just flat white) as with quick images of normal material you might not tell. I think of it this way: If someone drinks their coffee all the time with sugar or Coffee Mate, they're not going to like plain coffee (or just coffee with some cream, but no sugar). If you just give them both right after each other, no matter how good the plain coffee is they won't like it. Now if they spend a few weeks adapting to coffee with less and less sugar and additives to get to drinking plain coffee, now they'll notice all sorts of nuances in the plain coffee (if it's good, of course). They might go back to the coffee mate and find it overly sweet and fake tasting compared to the plain coffee, which before they couldn't stand.
Of course, that isn't for everyone. Some people don't like plain coffee no matter what, just like I don't drink scotch neat no matter how good it is, and I usually prefer an old fashioned to straight bourbon given the choice. But if you take someone that's used to a very bright, over blown, highly contrasty image and give them a totally neutral image, they'll have a similar reaction to the coffee drinker since that's what they've been used to for years. I know it sounds very pompous to say "You don't know what you like, just watch it neutral", but you can say "Just try it for a week and see what you think, then if you still don't like it you can go back", and often after giving their eyes a week to get used to the different image, they'll see the details and such that they didn't see before, and the vivid modes will now seem harsh and blown out. Some people still won't like it and will go back, but if you just see a flash of neutral for 30 seconds at a time, you almost certainly won't like it for the reasons I mention here.