The Avenue Pad 6 is awesome too, but the Avenue 3 wins because of the button placement. If a game uses Run or Select, like Dracula X item crash, Avenue 3 rules over all! If you play those games on an Avenue 6, I think the Run and Select buttons are too far to quickly reach with your right thumb. Therefore, the Avenue 3 (or standard pad) is better. Of course for 6 buttons games, the Avenue 6 rocks.
My scientific grading system:
Games that only use I and II buttons:
Avenue 6 = Avenue 3 > Standard pad
Games that also use Run or Select buttons:
Avenue 3 > Standard pad > Avenue 6