With random rolls, what is the % chance of getting quality gear, as you put it?
Math points to you being wrong here. So does gameplay from Destiny 1.
Example:
With Random rolls, the chance goes down, so you will spend more parts to get the roll you want, not less. Can you still nail the best possible roll with 1 turn in? Yes absolutely, but the inverse is also true. (an infinite number of turn in's before getting it)
This was a change to make you grind more, we all know that, its not a change to get you better gear. I am fine with increasing the amount. 40 parts was a solid number to strive for.
So lets say you get 2 parts per weapon dismantle.
Previously, every 20 pieces was a chance for decent purple at your current LL or slightly higher.
Now its every 50 pieces.
From what i saw, the # of parts you get per dismantle has not increased.
Also for the record, I am absolutely fine with random rolls. I am not fine with the continued inflation of engram costs that has happened every DLC this game.