The base duration for these traits is listed 6 seconds and 9 seconds. However you get only 6 seconds of both swiftness and fury (regardless of increased boon duration perks)
With my build I have about 25% increased boon duration (which for me makes them say 6.25 and 11.5 seconds). Note that the math is incorrect for one thing and Tail Wind should be listed as 7.25 seconds not 6.25 seconds. In my traits Furious Grip appears correctly at 11.5 seconds. HOWEVER i only get 6 seconds of swiftness and 6 seconds of fury on weapon swap regardless of boon duration increases. This is less than the base of the listed “9 seconds” on Furious Grip.
I use a weapon swap build for pve so it makes a fairly big impact since i am missing 4 seconds of fury out of every 10 seconds.