It boggles my mind that I can churn out great briskets every time, yet the chuckie gives me problems.......
They can vary a lot from cut to cut. I've had good luck with 7+ pound chucks that have a pretty heavy fat grain in them. I rub with Montreal Steak then smoke them for three hours or so to get flavor then foil the rest of the way until about 195 IT. Then, FTC and the IT usually runs up to at least 205 range. Haven't had a dry one doing it this way and the flavor has been great -- good balance of beefy flavor with nice smoke level.
Hub
I think you hit on something that we may overlook when cooking chucks- More mass of meat allows for better moisture retention with this cut, because the grain of themeat is mostly vertical, and not as long as in other cuts allowing more moisture to wick out than in say - pork butts.....
So - bigger would be better for chucks for sure Hub. Sound logical to you?