Less brass life is a myth...if you size correctly. You'll get loose primer pockets or split necks before a case head separation. The reliability part of it is self explanatory. Once you start competing and points matter to you, reliability becomes more important.
In all of my rifles, I have seen no difference in accuracy between FL and neck sizing. If you had a benchrest rifle with a tight, neck turn chamber, and were as a shooter, able to shoot in the .2's consistently, then you may notice a difference.
GAP Team Shooter 5