Thanks to all for the helpful and encouraging suggestions/ recommendations. I will check on the UAD Apollo sub-forum to see if anyone is successfully running this hardware under Wine or one of it's variants. But probably I'll end up buying the entry level MAC version and sorting out the Audiophile. And if I find time I may sip a bit of Wine.
Chris wrote: "I'm afraid that having one license for software on different platforms is the rule rather than the exception. (But there are exceptions! Notably when some subscription is involved.)"
Since my software licensing experience is mostly limited to music software, I can emphatically say that this is not the case with major music software companies. Let me list the programs I own that provide cross-platform licensing: Pro Tools HD Native, Cubase Pro 8.5, Ableton Live 7, Reaper, Sony Acid, Rapid Composer, Native Instruments Komplete, Slate Digital, iZotope RX 5, iZotope Ozone 7, Spectrasonics Omnisphere ... and I could go on and on and on.
"Not that licensing is a difficult topic in the Mac World. Apple's idea is: to pay once for a product in the App Store, then use it on all systems tied to your Apple ID and have all future versions included in that deal. Many developers can't live with that, and sell their products not through the App Store,present an upgrade as an entirely new product, or both. Besides, there may be slightly different features in App Store and own-store editions, due to the "sandboxing" that Apple requires.
I have found much to dislike about MAC O/S due to its lack of backwards compatibility and its near abandonment of desktop users in favor of IOS. It perpetually produces new versions without regard or communication with its 3rd party software developers that break programs. Sierra is still 'verboten' by most of the companies I noted above. I use MAC O/S out of simple necessity.
"Especially in the case of music software, I would recommend buying the native Mac edition, as I feel that Apple has integrated MIDI more in its operating systems than Microsoft. Using WINE or CrossOver couldn't change that."
I don't believe this is true since Win 7. I successfully ran a Win server with a combination of 12 virtual and physical MIDI ports operating various multitimbral virtual instruments, sound modules and other devices in my studio. However, the one clear O/S advantage MAC has is Core Audio and the ability to aggregate audio device drivers. It can be quite useful.
"A more general (off-topic) remark on software for Apple's operating systems: there is a habit of many App Store apps going on sale for a short spell (even hours), and there is a habit of certain websites temporarily offering bundles at greatly reduced prices. I can't remember much music software in either."
Thank you for this. I have noted this trend especially in plugin producers and take full advantage of discounts from time to time approaching 80%.