Brined Turkey

I wonder if the brining helps keep the turkey moist? Or is the main factor keeping an eye on the cooking and avoiding overcooking the turkey?

Anyway, I recently attempted a brined turkey for an large family gathering by making a few modifications of this foodnetwork.com recipe.

14 lb turkey was brined overnight in the following solution:
1 gallon water
1T ground cloves
1T ground ginger
4T cracked black peppercorns
1T cracked coriander
1T cumin
12 bay leaves
1 pound kosher salt
8 ounces brown sugar
Bring to a low boil to get everything dissolved.

Stir in and mix well...
16 ounces honey
24 ounces maple syrup

Add this last...
8 ounce port wine

For the turkey stock:
Fry up turkey neck and gibblets in some olive oil.
1/2 C port wine
1 C roughly chopped onions
1/2 C roughly chopped carrots
1/2 C roughly chopped celery
2T rosemary
5 peppercorns
Add water and boil for 90 minutes adding water as needed.
Strain into container and add water to yield 4 cups of stock

Butter to rub on turkey:
1 stick butter
2t powdered garlic
1t rosemary leaves
2t sage
Melt and mix and set aside until turkey is ready to go into the oven.
When ready, rub butter under the skin of the turkey.

Stuff into turkey:
2 apples, quartered and cored
1 onion, peeled and quartered
2T rosemary
2T sage

Place in roasting pan:
1 C cubed carrots
1 C cubed celery
1 C cubed onions

Roast turkey on top of vegetables 325F until 160F.

To make the gravy from pan drippings add:
3/4 C Madeira wine
4C turkey stock as described above
1T thyme
Bring to a boil and thicken with corn starch.
Salt and pepper to taste.