I do agree that of all the amps I've had, the Mark IVs really played the best with the ~05-20 V30s. I also agree that this is completely personal preference, and I'm just here to share my experience- which may be different than yours. And that's OK.
Both of the '06 cabs I had, at one time I absolutely loved them- until I started getting better at close mic recording, got some good studio monitors & really started paying attention. They quickly fell out of favor for me and eventually got to the point where I did not enjoy playing them compared to my pre-04 loaded cabs. Around this time other internet people started pointing out the differences as well, and what I was seeing at home was in agreement. So, they had to go. I had even originally recorded the band's first three songs with one of the 06s and later when we got to recording the next set of songs, after showing the difference to my audio engineer we both agreed that the difference was huge & we should reamp the first three (along with the next 4) through the older cab. The reamps are in mastering now, I can share the comparo later when they're done.
To the question of "who is an expert on tone?" My vote would go to experienced sound engineers. They are in a position to not only be exposed to everything, but are professionally responsible for finding the best tone for their clients while at the same time not wasting time (money). Guys like me who have had butt tons of different cabs have a lot of experience, but at the end of the day we're still amateurs. Also, consider that what a lot of us are doing here is chasing the sound in our heads, which is most likely an album tone. This mean it's a tone that was most likely close mic'd by a professional audio engineer. I highly doubt players are chasing a tone from any of our YT channels..