Japanese vs. Korean Joystick
The Japanese joystick has a ball top, while the Korean joystick has a bat top that covers most of the lever. Korean joysticks have no gate, allowing circular movement, and Japanese joysticks are versatile.
The Japanese joystick is more popular worldwide, while Korean joysticks have a niche fanbase that mainly consists of Tekken players aiming for a perfect wavedash.
If anything, you can buy an arcade stick with a stock Japanese joystick while having a Korean joystick on the side that you can switch to whenever you like.
Square vs. Octagonal Gate
A square gate is easy to work with, but the range of motion is limited because you only have four points to hit. On the other hand, the octagonal gate has a steeper learning curve, but its range is extensive, making it popular with serious fighting gamers.
Square gates emphasize the four main directions of forward, back, up, and down. So, if your character of choice involves a lot of those directions, then a square gate could be worthwhile.
With a square gate, some might struggle to find the diagonal points. In that case, an octagonal gate would be necessary as it makes it easy to find the diagonals.
There is a lot of precision involved with an octagonal gate, and with a square gate, a player can put less effort without sacrificing precision. In other words, octagonal gates may suffer from diminishing returns if you put a lot of effort for little reward.
To explore this topic further, you can check out our list of arcade sticks with Korean joysticks.