Can someone explain Falcon Dive notable ?

I need information on this because I guess I did not understand how that works. I have 10k accuracy rating on my main skill listed under "Main hand accuracy rating". With this notable " 1% increased attack speed per 250 accuracy rating " the increase should be 40% right ? (10k/250). But with or without the notable, the change in attack speed is barely notcieable. Is this normal ? what can I do to increase the attack speed stat ?

Commenting to follow for an answer as well. Throwing a theory out there...it's your flat acc pre buff