I don't reccomend Steinberg products for Macs, they have the worst performance, when compared to other Mac DAWs.
Logic runs fine on a G4/400, minimum for SX2 is G4/867 dual processors reccomended.
It's also plauged by over 100 bugs, over half were contained in SX1.
the reason Mac users are not complaining, because there are so few left. Most have moved on to better performing apps.