I personally don't like games that limit strafing to much as RvS do. Look, as a combatant you do not only move forward, sometimes you move forward, but turn your upper torso slightly, or much to the left side, which let you shoot at sideways targets and still allow you to move. AS a right handed person you have slightly problems to do the same to the right side, which would lead you to a real strafe, which must be somewhat slower, unless you solve thet problem by swapping the weapon.
Of course weapon accuracy, stamina should be worse at that point, but starfing, as done in real life is very valid, same as jumping when it is implemented like it is done in real life.
p.s. I pesronally even hate the fact, that you can't 'strafe' when sprinting, in that case this kind of strafe would be nothing more than a head turn, while the whole body is directed where you moving to.
This feature would be very good, bo give you the ability to keep the location better in track when sprinting.
Same I dislike in AA:O, but there you can run forward + strafe, which workes in a way ok.