One big difference I have noticed is that they seem quite ready to admit their machines are not going to have a 'comeback' but are happy to keep using them, upgrading them, and developing for them simply because they enjoy it and they like the computers / OS.
This is why I have an amiga these days after years only in the PC space (I was amigaless from 1997-2004). I enjoy tinkering with old hardware (amiga and PC) and have a special place for the amiga. It also helps me as I have an example of a 68k processor to tinker with programming.
Even running OS4, I still can't concider the NG amigas (AmigaOne for example) as an amiga. It is basically a PC motherboard with a PPC, a PPC chipset and a custom rom to me. An amiga isn't an amiga without the custom hardware IMHO. It just feels like a bit of an imposter IMHO.
Anyway, I wonder how strong the Atari ST following is these days?
