NO, a stock Atari ST is actually faster then a stock Amiga. The Amiga runs at 7.1 MHz and the Atari ST runs at 8 MHz, .9 MHz faster then the Amiga. Also, I actually like using my Atari ST computers more then my Amiga computers, but I love them both
Your correct, and being an Atari expert you could also agree it may have had a chance to show that extra difference in gaming, but did it? well not when the ST went anywhere near sampled sounds, the difference was lost and then some.
As said in a previous thread, the Amiga started to shine when it stopped getting ports from the ST and the game developers started to dig into that fantastic hardware available.
The Amiga demo scene always had that :-)