ManicX, the A1000 was released at the same time as the Atari ST. It was the A500 was released 1.5 months later. And why would you want to use PC disks? The Amiga could store more data on them as well.
An external PSU is an advantage in my books, if the the thing blows up, you could just buy another. If the ST's one did it would be a major headache due to its integration.
The YM chip was perfectly suitable for the Amstrad CPC - an 8Bit computer. Not for a supposedly 16bit one. The Atari ST is more 12bit in all honesty when you compare it to the Amiga's stereo sound.
And TOS was blatently worse than OS1.3! Please! Workbench1.3 had features that were only incorporated by Atari into 2.06TOS 6 years later! An inbuilt OS is also a disadvantage - far too rigid, having your OS on floppy is a lot more flexible. People may criticise the Amigas poor HD support but going SCSI was a better bet than the bizarre contraption called an Atari ST hd.
The Amiga's dominance of the gaming industry was actually what kept it going and what effectively killed of the ST. Its nothing to be ashamed of.
I agree that both Atari and Commodore were as inane as each other and both their 16bit machines had strengths and weaknesses, but the Atari ST had way more.
P.S. I was an Atari ST "user" between my Amstrad 464 and Amiga 1200, so dont think i hate them or anything