Another draw back with using CS for astro on mac is a lot of the nice plug-ins that exist on PC (like Russel Croman's) arent available for the mac.
Although the popular Noise Ninja is available for the mac
http://www.picturecode.com/
I would say the biggest draw back for mac owners is the lack of readily and widely available bootlegged stuff and poor service in up to date serials/cracks compared to PC's
, naught naughty PC owners - not that i condone that sort of thing
EDIT:But then so called 'Dark Pyramid' just arent into macs it seems.