My take:
Demos should show what the HW can do and how good it is
understood by the coder.
So REAL demos only run on fixed HW like C64,A500,A1200 or
Phase5-PPC+Permedia. Consoles of every type are also quite good
for it. Demos on PC or CGX/P96 sounds even more useless than
demos allready are.
Don't have th HW ? Use a emu, or watch the mpg.