That's very well said.
Especially within context of saying that in 8th Ed., Vehicles were changed to simply being 'big models' with higher Toughness and more Wounds, and that you didn't like that, or just a Monster with a different Keyword. Whereas I, did like it.
I think to clarify, my dislike of the AV system comes from:
1. S4 vs. AV11 (or S4 vs. T8, for Monsters) sets up a bad meta that I just didn't like and wasn't at all inclusive. I've already played through that edition. I don't want to go back.
2. Streamlining AV into Toughness, makes the game simpler and easier to understand in a way that doesn't - IMO - diminish the game. However, I think the issue also lies in the ****ty To Wound table, and the fact that in the current game, nothing is over T8. Whilst S9 and 10 (and Mortal Wounds), do exist. The problem isn't that Vehicles have a Toughness value. The problem is that Vehicles have a Toughness value, whilst also removing their...Toughness (see above).
Making Vehicles or Monsters T9 or even T10, would actually improve a lot of the current problems with Vehicles and Monsters just dying and being generally terrible. The issue isn't lack of AV. The issue is lack of T10.
Remember, AV14 at the time was equivalent to T10.5. That's what made Land Raiders so good.
Well, ****. There you go.
The problem isn't that AV is gone. The problem is that all Vehicles got nerfed.
At base, AV10 was equivalent to ~T7. Clearly, there are Vehicles in the game that were AV10, that are now T6 - or even 5 - and it's worse from there.