Raise 3.5*bb or 4*bb PF in cash games

[SirThomas]

I have always raised 4*bb + 1bb pr. limper PF when I have played cash games.

But I see more and more good players who only raises 3.5*bb PF.

For example I often see people raise to 14$ instead of 16$ on NL400$.

Why is that? Is it because blind steals become more +EV and when people play back at you, you won't lose as much?

Because when I think about it I think that raising 4*bb is more +EV, since you will get a bigger pot on the flop when you take it down with a Con. bet and it will be easier to make a pot big when you have a big hand etc.

What is best? And does it even matter?