1984 Mac OS was barely more sophisticated than C64's GEOS + 1351 mouse and was silent and colourless so 128k was enough for that singletasking Apple fashionista £2500 wank. The 520ST ass raped the original Mac on every level possible (price/performance/speed,colour/OS,max res, appearace) within months...total wipeout....and STs 8mhz CPU is the only aspect it exceeds Amiga.
Oh please. Look, I'm just as fond of memories of the Amiga as anyone else around here but Apple was years from making fashion accessory computers. The Lisa, then later the Mac, were an attempt to put what Xerox was doing at Palo Alto on the desktop of ordinary people. If they hadn't bothered, nobody else would have, and we'd be having this discussion in VI or some other godawful text-only medium.
Yeah, the 520 sure was a winner - that's why it ... uh, I'm sure I can think of something it did better which is why it's still around and the mac didn't last except oh wait it isn't and the mac did.
And finally: the original 128k Mac did have sound Virginia.
It's one thing to say "Man, the Amiga was a neat computer". At the time you couldn't have convinced me I'd have the point of view I do now. Except, you see, I grew up and can look objectively at the way things really were, not from inside the Amiga Reality Distortion Sphere where no other computers exist or if they did they were rough-edged abacuses made out of iron that delivered hepatitis and painful electrical burns when people tried to use them.