I used X-arcade just with USB adapter (no way to make it work via Ps/2 method) and i never noted any lag.
years and years ago, a lot of games a lot of pressing on it!
It's new as the day one.
some guys have modded it using SANWA stick and buttons (for beatem up i think)
I solved buying another ARCADE STICK of Mad catz (SF4 tournament limited edition with sanwa stuff)
No credit card limit for passions! (as long as there is money in it..