I went ahead and ordered a SNES PowerPak, based on how impressed I was with the NES PowerPak. I don't think the inconvenience of having to manually save to memory should be dismissed, because it's definitely an inconvenience. But it's one I'm willing to deal with.

I also ordered the Atari RetroPort while I was at it. He also offers a Genesis retroport. Is there actually a difference between the products, or will the Atari one work with a Genesis controller and all 6 buttons?