Originally Posted by I is a moose
I've injected, rubbed, and brined briskets on several occasions, and there are no noteworthy tenderness differences between the two, moisture was negligibly better in the brined brisky, and the injected was okay.
I think your dryness issues stem from your temperature: 250 is simply too high in my opinion. 225 is the general consensus, 215 is what I do.
How much trimming of the fat do you do? I've recently stopped trimming my briskets altogether, and remove the excess fat as I carve, it works great.
How long do you let your rub sit on the meat? Overnight is the minimum, 2-3 days is ideal.
Do you "inspect" your purchases? An ideal brisket for smoking will have a great deal of flex.
What is your smoker make? If the heat source (coals, element, burner) is on the bottom, then it helps to flip the roast so the fat cap faces the heat for insulation (there is debate about this).
How long do you let your meat rest for? Alot of folks will say that it's best to wrap in foil after removing it, then wrap in towels, and store in a cooler for a couple hours. This works wonders, because it gives the meat a chance to rest, redistribute the juices, and finish everything off with an almost braise, making a juicier, more tender finished product.