Thanks for the info. One more post for clarification if you don't mind DG - and Dietz this is not a complete departure from topic as I'd like to know whether MIR Pro will operate properly along with and on top of everything else on the Mac, especially for demanding scores ex. Mahler 2nd.
I had a look at those pages you referred to and the comparative results were not as damning, although slightly in favour of Windows and then only DAWs available on both platforms were considered (of course); it doesn't say much about how Logic compares for similar tasks, although I read little and mostly scanned the material (quite a lot of it there). Also, from what I understood, Microsoft became more efficient than Apple only after the introduction of Windows 7, if you switched back in 2004 I am unclear as to why you decided thusly back then (if reasons were pirated software or other of course this has nothing to do with comparing the two OSs)
When you say low latency is all important to you because you play your compositions "live", what do you mean? Don't you play/sequence one instrument (even polyphonic) in at a time? Are you saying that Logic and MacOS are inadequate for that? My M.O. involves importing the MIDI of a Sibelius score into Logic and working on it thereon. So my work on the DAW consists of EQing, automation, etc. and mixing, but not with frozen tracks. All tracks are "live" tracks right up to bouncing. In addition, not mentioning RAM at all in your post, makes me assume that it is not a main concern. I'd appreciate your - and everyone else's - insights.