Personally, I'm on SMP. APM doesn't work on SMP, whereas ACPI does. So I "need" ACPI if I want my computer to be able to do a software- controlled power down.
If your hardware has APM support, you can boot with "apm=power-off" to get power-off support with SMP.
-- ======================================================================== Ian Pilcher i.pilcher@xxxxxxxxxxx ========================================================================