No it's a good question. The stock Dreamcast pads (and most 3rd party pads) have analog shoulder buttons. If you hack the analog shoulder buttons, there is lag from when you press the button and when the game registers your input. So if you want to build a high quality arcade stick for Dreamcast, you can't use pads with analog shoulders.
There are very few 3rd Party Dreamcast pads that have six digital buttons. There are only three that I know about. The first is the Quantum Fighter Pad, which is in fact does NOT have 6 digital buttons, despite its layout (two of the buttons on the face are programmable buttons, i.e. macro buttons). The second is the Innovation Dreamcast Pad, which is as good as the Madcatz (so I've heard) but much harder to find. Finally, there is the Madcatz Dreampad, which has 6 digital buttons, and huge solder points actually pre-drilled through the PCB. It is almost as if they were made to be hacked.
Long story short, if you are a Marvel vs Capcom fan, and you want a quality custom stick for Dreamcast, this is the pad of choice to rip the PCB out of
