The bad news: P5 Mac version 1 is extremely slow compared to P5 Win; see Burton's benchmarks in this forum and elsewhere. Maybe the next release of P5 Mac will be better written, despite the chaos that must have occurred during the takeover of CL by E-Frontier. What we're hoping is that they can develop a stable group of remedial programmers who can bring the code up to speed, like the example of Carrara, which runs faster on OS X than on Windows machines. The good news: Win XP, ME, 98 etc. are all inherently unstable compared to OS X, provided the OS X system has been checked for any hardware conflicts, bad kernel extensions and other problems that cause instability in OS X. Nor are there any viruses or worms for OS X yet, although there is one harmless trojan.