What do you mean, which one would I use? I was alive back then, and I did use* Amiga OS. If I had to go back to 1985, even with hindsight of it eventually being a dead end, I'd pick an Amiga again, no doubt. It was far and away the best system of its time.
(* Technically, I didn't use Amiga in 1985, but only because I was a broke kid, and couldn't afford to upgrade from my Commodore 64 to an Amiga until a couple years later...)
