A T configuration sure makes it easier to rig, but I completely agree with PrimalBeans - it's more important for your model to look good, than be easy to animate. I would tend to use a T when the character has a lot of movement in their arms, say for a platform game character. But for a FPS, I think that a slight bend in the elbows, with the arms down at the sides is good - try and think of a neutral pose that would go into holding a gun or weapon switftly.
Shoulders always trip me up, they can deform so much and so badly - getting them right is time consuming, but time well spent I think. Knees are a problem too, but not as much. Try and think about how your model will deform, add in some extra polygons, be clinical with your edgeloops too.
![](/images/emoticons/minivan.gif)
Health, Ammo, and bacon and eggs!
![](/images/emoticons/minivan.gif)