Connecting USB conrollers/sticks to PC using the PS/2 (keyboard/mouse) ports?

Possible? I noticed my mouse responded a little better when using the PS/2 port, and apparently some PC gamers are in favor of this generally. Mainly for keyboard reasons, AFAIK.

I was wondering if there’d be an improvement if I were using my modded 360 stick via one of the PS/2 ports instead, but I can’t find a way to test. I have a standard USB to PS/2 adapter, but it didn’t seem to work. And there are people who breakdown and mod old keyboards, and/or build custom controllers from them (parts), but that seems like slightly too large a commitment.

Has anyone tried this before? Any noticeable results?

It does not work that way.

Only select keyboards and mice work in both ps/2 and USB as their encoders inside (the chip on the PCB) support this.
Only other devices that support ps/2 are older scanner beds and hand scanners used for POS units.

Normal USB arcade sticks does not support the ps/2 port, and the PC does not support game controllers though this port either.

Now there only way a Arcade stick would work as a keyboard is you have to get a keyboard encoder, wire up your joystick and buttons to various keyboard keys on the encoder and plug that in as your PC’s keyboard.
(yes there are PS/2 splitters). This mention was really popular with the Mame scene but discouraged in the FGC