Since you asked... Lol...
As related in a past post on the matter, I guess it depends on the aim of the demo. If your looking for 'catchy', I'd definitely stick to your older demo vids, more specifically, this one:
https://www.youtube.com/watch?v=oBrKiQISBqI
I loved all your vids when I was first getting into MTS - they were very effective in drawing me in at-least!
And, as far as functionally useful demos, I'd make the following recommendations:
1) Not so much 'noodling' - a perpetual solo/lead line gets old really fast, and does little to demo the versatility of a product. Clearly, you want to demo lead tones, but be sure to include at-least half rhythm. Basic power chord stuff, full open chords to demo articulation/note separation, some drop tuned riffs, chugs, etc. Even the best of lead players still only get a few precious seconds of solo time in most songs (if any at all...), so I'd devote the time to it accordingly.
2) Use different guitars. Personally, if you can demo a product using a strat-type guitar (preferably an actual strat w/SC PU's), and a Les-Paul type guitar (again, preferably an actual LP), it really helps to demo the sounds most folks can expect, as most have one of these two, or a variant. One can make mental 'adjustments' to get the feel for what their guitars would sound like with the product, if they do not have a strat or LP.
3) Use guitars (and other gear not specifically demo'ed) that are widely known. For instance, I believe you used Waterstone (or similar name?) guitars on a bunch of past demos. I for one, have no idea at all what a waterstone guitar sounds like - I can only speculate based on it's looks. So, as above, I'd really stick with the mainstream heavy hitters - Strats, LP's, Tele's, maybe a 335 here and there - as the sounds coming out of them are predictable and familiar, and gives the viewer a better idea of what the mods would sound like minus coloration by a strange guitar (even if is a great one).
4) Demo all functionality of the mods - all modes, switches, sweeps, through various EQ settings, etc. i.e. Johnny Wadd's MarkUs video shows only the clean side, and I have yet to see a comprehensive demo of the drive side of a MarkUs which is what 90% of folks will be interested in most.
5) Include all gear used in the description: Mod(s), amps, tube types, guitar(s) used, including pickup mfg and model, cabinets, speakers, mic's, processing/production gear, pedals, interface, DAW, etc... A-lot of YouTube demo-ers do this, and it's very helpful. And, as a bonus, you can draw a-lot of traffic from non-MTSers, as they are perusing for demos of any of that gear (tubes, guitars, especially pickups, pedals, etc.). Great way to bring outsiders into the fold.
Here are a couple examples of folks who I think do great demos:
https://www.youtube.com/watch?v=w1iNAtEmeSo
https://www.youtube.com/watch?v=CMT6TYkUgSY
Just my 50 cents, lol. Hope it helps...
