Why does a wagyu brisket cook faster than a choice brisket?

[NGS]

I completely agree that every brisket is unique in the way it cooks. Which is due to there being so many variables spanning from the cow (genetics), stress levels at slaughter, and what the cow ate to all the other past slaughter events and brisket attributes that are discussed in the forums. But I do believe that each variable can be broken down as to its effect and ballpark magnitude of that effect on how any particular brisket cook turns out. I believe that the final result of any particular brisket cook is dependent on the sum parts of all the variables - many we have control over and some we don't.

[NGS]

Typo correction above - post slaughter not past slaughter in second sentence

[NGS]

As Aaron Franklin said once, bbq can get really geeky

[Huskee]

I've had a Choice brisket take 12 hrs until cambro-ready and the next one I did (Choice also) was ready for the cambro at 4.5 hrs in, aka 10:00 a.m! It's sickening the variations you can get. Especially when your time table doesn't allow for such leeway. I had to cambro my last brisket for almost 8 hrs until dinner. Still great but c'mon!

Moral of the story- Candy is right on. Don't go by a clock or a pre-set recipe, and with brisket even a thermometer wont tell the full story. It's a feel thing, it's a pay very close attention to ALL factors thing.

[NGS]

Yep! Aaron Franklin's briskets are typically off of the pits around midnight with his restaurant opening for to-go orders at 10:30. They are rested and held a long time before serving but it is the best brisket I have ever eaten at a restaurant. Taking the briskets off that far ahead also allows Aaron to have time to cook the ribs before opening.
Mueller's (located in Taylor, TX) holds their briskets in Cambro's - wonderful brisket as well. Many of great central TX places holds the briskets for hours before serving for two reasons - Huskee hit on one of the reasons, a time cushion to make sure they are ready before serving. The other being that a smoked brisket is just a better product after resting.