Its reallllllly efficient, I personally use and 1 hander and no shield, and I can keep with most agi oriented 2 hander due to the basic speed of my weapon being faster, compensates for the lack of WPF.
Piggy backing on this, agility is a double edged sword. Your athletics makes you move faster, can give you a bit of movement speed bonus but you'll pay less attention to correct footwork direction usually by crutching on the speed. it makes you a worse player. Your athletics means you move faster at the enemy too, so your speed bonus works against you as well, especially when you step into their swing...
Higher WPF does not allow you or them to spam. I regularly double-swing people on my 36/3 build and destroy them because direction you step and swing in > speed of the speed and direction you step (besides it is a very small amount you get from wpf..). Weapon speed effects your attack speed more than WPF. Remember that.
Let's say I'm fighting a 15/24 agi 2h on my 36/3 build. This is a more extreme example, but you'll get the point.
1) He tries to circle me. I match his turn rate because athletics doesn't touch character turn rate, and he ends up walking into the direction of my swing and gets onehit.
2) he tries to backpeddle me. I don't chase him so he just looks like a coward playing with himself 10 feet away while I go back to killing dudes. If he comes back we'll fight like #3.
3)He fights me straight-up and is at a severe disadvantage due to needing 4-8 hits to kill me, while I need only one or two to kill him. He does not swing any faster and can not break the block-swing cycle.
4) Due to his low HP amount he can not risk to do chambers, while I can risk 2 or 3 chamber attempts safely while knowing I won't die to his weak swings. If I chamber any of his side swings I'll win the fight.
5)If he glances due to his low damage, which is likely, I automatically win because he can't block my swing.
6) He tries fancy footwork side step spam stuff and just steps into a swing and dies.
7)He gets to fights a bit faster than me. If a team of strength builds fight a team of agi builds with equal skill, the strength will win every time. getting to the fight faster means nothing if you can't take 2 hits when you get there.