i havent noticed, but i havent extensively tested it either

i would imagine the degradation would be the same as using a component, s-video, or composite switchbox. ive noticed a far bigger degradation by using crappy cables, than i have with a switchbox. im sure there are videophiles out there that can scientifically measure how good a signal is and show how much degradation a switchbox produces. but the leap in quality especially for the genesis and neo geo far outpaces any loss a switchbox is responsible for.

funny story on auto switches, my friend had an automatic scart convertor, and it would strangely power up other consoles attached to it, and then it would get a weird mixed signal. it couldve been a faulty box, but "signal muckery" (awesome term, btw) was the norm with the auto switchbox.