In my opinion (and I have no real expertise other than the percieved genius in my own mind :crazy
brining's pretty easy with poultry. You can brine pretty much anything, but chicken and turkey will take the brine much quicker and easier that other meats like pork and beef. I think it has something to do with the cellular structure of the meat.
Here's a list of brining times of different meats and cuts:
[FONT=Arial,Verdana,Helvetica,sans-serif]
Whole Chicken[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]3-8 hrs[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]
Chicken Pieces[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]1-2 hrs[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]
Whole Turkey[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]12-48 hrs[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]
Turkey Breast[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]4-8 hrs[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]
Cornish Game Hens[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]1-2 hrs[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]
Pork Chops[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]2-6 hrs[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]
Pork Tenderloin[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]2-8 hrs[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]
Whole Pork Loin[/FONT][FONT=Arial,Verdana,Helvetica,sans-serif]24-72 hrs[/FONT]
Since chicken pieces only take 1-2 hours and pork chops take 2-6 hours, I'm equating that to pork taking longer.
SOOOO.....
I've injected pork butts, but I've not taken the time to brine one. With chicken, though, brine is easy and quick (relatively speaking). If I'm doing wings, I brine for an hour. Whole chickens get brined for about 5-8 hours. Basically, if injecting, you're just injecting a brine but the brine is among the meat tissues instead of incorporating into them. Brine works differently.
I prefer to inject larger cuts like pork butt, but brine chicken and turkey. I even brine whole turkeys.
Here's a GREAT bunch of info on brining (where I pulled the table above from):
http://www.virtualweberbullet.com/brining.html