Fightpads and Mods

Foreword: "Play on stick" isn't helpful advice. If it were, I wouldn't have posted this.

A friend of mine uses the Madcatz XTekken 6-button pad (360), and it's adequate. But the buttons and pad lack sensitivity and seem to wear out quickly - especially the d-pad. Can anyone suggest a better pad that has more sensitivity and/or durability? I went through another thread about pads and a lot of the links were 404'd, but several people suggested the USB Play SEGA pad which emulates a SEGA Saturn 6-button. The problem is that the top buttons are much smaller which could make fighting a problem. At one tournie someone had a grey USB pad with uniform buttons and an analog stick instead of a d-pad, but it looked like some bargain bin item with no defined markings.

Alternately, information on modding the XTekken pad with better buttons and d-pad would be equally useful. If anyone has links to buy replacements of the oversized face buttons or replacement/better d-pad, please post.

He plays primarily on Steam/PC, so there's no console restriction. Any links and info are helpful.