There are five elements to a brisket flavor profile; the meat purchased, the rub used, the smoke wood, injection used, and spritzing ingredients. Personally, I don't inject or spritz.
Injecting and spritzing are all about an advanced flavor profile. Yes, some unpronounceable ingredients can break down the collagen structure in the meat. Salts can help the meat retain more cellular water, but melted collagen and rendered fat make brisket juicy, not cellular water. Nothing guarantees a tender, juicy success unless you know how to probe a packer brisket to tell when it's done, then understand what happens during the resting period. I don't inject or spritz because the natural flavor profile of a beautifully smoked brisket is all the flavor I need.
If this is one of your first packer briskets, which I get the sense it is, keep it simple. Rub, smoke, wrap during or after the stall (a later wrap helps keep the meat from tasting like pot roast). Start probing through the wrap when the IT is in the neighborhood you want. Keep smoking until the FLAT probes tender (the point will fool you). Then take the wrapped brisket, put it in a pan, and throw it in a 170F oven to rest for 3-5 hours.
Too many believe that a 3-5 hour rest in a 170F oven will overcook and dry out the brisket. Nope. It may overcook the brisket, but it will be juicy, tender, and a little crumbly. It will still be the best brisket you will have ever eaten. If you took the brisket off a little too early, which is by far the most likely thing to happen, the oven rest will break down the remaining collagen and deliver the most juicy melt-in-your-mouth brisket that will rock your world.
Have a razor-sharp knife handy to carve the meat. An electric knife works well too. Carve across the grain and bask in the glory of the people you feed.
You've received a LOT of great ideas in all the posts. All smoked briskets are edible and usually better than what you can buy locally. But, when you taste a melt-in-your-mouth flavorful brisket smoked to perfection, it can bring tears of joy to your eyes.
Let us know what you did and how it turned out.