I believe we had this discussion before, but I personally find the stat gain from the SkillSpeed to be better than the wasted 41 accuracy. There is no other combination of gear that still gives the crit and det numbers we have that allows you to properly use that 41 accuracy.
Here is the difference in stats when swapping helmets as you propose. The top one is the guide's BiS list, the bottom is yours.
DEX - Acc - Crit - Det - SkS - Vit (just incase you did not know the order for the stats from Ariyala's page.)
http://imgur.com/B4Kgh6v.jpeg
http://imgur.com/BetmFAP.jpeg
With an accuracy cap for a4s of around 650 to 655, i personally do not see the swap in helms to be worth the 17 crit raiting