I'm kinda curious about the various functionality of the different carts as well. Been considering grabbing one for the business so we can more easily test ROMs (we can flash them to new boards pretty quickly, but this would seriously speed that up, plus we wouldn't have to wipe the boards when we are done testing the ROM

)
Have really only considered the SD2SNES since it seems to have the most compatibility, but I'm not really sure now which would make the most sense for me. It's the most expensive, and obviously I'd like to spend less money if possible.