Well, actually, I have two different USB adapters for using PS gamepads and both leave something to be desired when we’re talking about fighting games. They introduce a delay in response that makes the overall experience kinda frustrating. I play the same game - Capcom VS SNK 2 - both on my PS2 and my PC - using nullDC, a Dreamcast emulator, using the same controllers - Dual Shock 2 and Logitech Cordless Precision Controller, and it’s unmistakably easier to perform combos and super combos on the PS2. My favorite subjects for testing the difference in a simple way are HCB/HCF 2x (e.g. Messatsu Gou Hadou) and Geese’s Raising Storm, which come off way more easily on the PS2, regardless of which of the two controllers I use (though I do prefer the Logitech one).
This pattern can be noticed in other games, and definitely not only when emulating a DC. I even changed the global USB polling rate from 125 Hz (8 ms between readings) to 500 Hz (2 ms between readings) by editing the USB driver (usbport.sys) under Windows XP, but though it may help, it’s not enough.
BTW, I tend to trust Logitech more than Microsoft or Sony when it comes to quality. That’s why I’m interested in hearing people’s experiences, especially when it comes to fighting games, which are the most demanding kind of games as far as I know. That Logitech Chillstream may be really something in terms of accuracy and responsiveness, or it may be “ok”, or it may suck. Also, the MS controller may be better than it in this case, or not. I simply don’t know. Do you?