Usually transferring files from one OS to another does not give ANY problems. It just work the same way on MacOS and Windows. The only expected issues might be with fonts - on Windows same font can have word 'Western' or 'Cyrillic' in its name or any another language group, when on Mac language group is not included into font name.
It's recommended to pack file into archive (PLA) to avoid unexpected troubles with libraries - but I never experienced any problems with libraries on Mac and Windows - they work identical. So, instead of packing files into PLA you can have PLN and libraries. Use archive when you archiving your projects (and plan to open the file in 5 years or something).
But the real problem you can face if you open your 14 version files in versions higher then 16. In version 17 was introduced Building Materials, that completely replaced fills in structural elements. And when you open an old file it creates library of Building Materials from fills - that just not looking nice and not comfortable to use.
Also since version 21 there is new Stair tool - all you old stairs from Stairmaker will be converted into new format - where you can expect unpredicted errors in geometry.
But it total - all goes really smooth without disasters. Write here, if you face any troubles. Here are plenty of people will help you.
