My biggest gripe with Youtube airgun channels is the shilling. It just seems to be inherent to it. The gun reviewer gets free stuff, but in exchange they have to be positive about what they're reviewing and as a rule the better the production quality of an airgun channel the more beholden they are to their corporate sponsors. I really like Airguns of Alaska even though his channel is kind of low budget, because he doesn't seem to hold back with the criticism and he knows enough to pass on relevant information.
One of the problems with the amateur airgun reviews is that so many of the people doing the reviewing simply don't have a clue as to what they're talking about. Another is wasting time on things that don't matter to the viewer. There's no need to spend minutes showing someone shooting groups or shooting over a chronograph. One or two shots is all you need to show and then simply post the shot group or the data where the viewer can easily see the results. Also, try and remove the human element from your shooting as much as possible. The audience really doesn't care if YOU shoot like Annie Oakley or like the A-Team. What we want to know is how accurate is the rifle. Shooting from a good rest or tripod, showing the distance and wind conditions, (and temperature for CO2), and maybe having another gun there for comparison is essential. If you're going to shoot groups offhand then we're going to want to hear about how the gun points and handles and otherwise feels in your hands. I do particularly appreciate the humility of MacabeSpeed though. There's something very refreshing about hearing someone openly admit that they are not a good shot. I'd much rather hear that and see an awful group than see some cherrypicked or faked one hole group passed off as being ordinary.
For me, there's nothing worse in an airgun review than someone who does his accuracy testing offhand at an unknown range and then acts like he informed me of something worthwhile.
And please, no unboxing! There's nothing wrong with showing the packaging something comes in if it's particularly good or particularly bad, but actually watching you open up a box and remove the gun from the bag is just a waste of time.