I think the hitbox is great if you play a charge character, e.g. Guile from Street Fighter.
To do his signature Sonic Boom, you need to hold back on the joystick for a short period of time then move it to forward and press punch.
On a hitbox, it's a lot quicker to do that motion since you just press and hold buttons.
Then for his signature Flash Kick, it's the same charge motion, but up and down.
If using WASD controls, it's a little difficult due to timing. You have to physically move your finger from S to A, whereas with Sonic Boom, you have two different fingers.
If using hitbox style controls, you would hold down S, then press the spacebar with one of your thumbs and kick together, which is much easier.
Here's a video that talks about the hitbox.