It's funny, at the time I thought there was a lot more parity between the ST and the 500 but when I watch videos of the two these days, I realise just how much better the Amiga was.
I'd always assumed the sound would be great on the Atari because it was midi-compatible, but I was horrified to hear how tinny and bleepy the sound effects were in a game I knew from the Amiga.
Oh, to go back in time and use that in an argument at school with my ST nemesis, Andrew!
Yeah, my old flame wars with Atari users were all largely based on vibes and spec sheets and screenshots in magazines and how ugly TOS looked, not on actual experience with the Atari... But I've been happy to be vindicated by various videos...
I somehow do really like the sound that some managed to squeeze out of that YM2149 sound chip in the ST though. It was an old low-end chip when the ST was new already, and most games do indeed sound like ass. But the people in the demoscene worked their magic on it to great effect.