Thanks Jan van B!
That is a very useful summary of your real world experience.
3 of your listed softwares are new to me, as above, and I guess it will take a bit of time to look at all of them in detail.
For OKmap, I see that there is a very comprehensive manual (some 230 pages!) with the software which could well act as a reference for anyone who has an interest in maps and digital mapping (such as me!).
http://www.okmap.org/download/okmap_en.pdf
It has one or two quaint English language expressions, being a translation from the original Italian I guess; nevertheless it is a great summary of the subject.
From a quick glimpse at this manual I would say that the software does everything that Basecamp/Mapsource do for the end-user; that's my first impression anyway.

Evidently, OKmap is produced at present for use on desktop operating systems and for the Apple products; maybe a version for Android will follow in due course (that will be why you use Oruxmaps for editing data on Android operating systems).

Update:
I have now skim read the 230 page manual for OKmap (it can be downloaded as a pdf file) and it is a very comprehensive explanation of the functions of the software.
Also, it provides a glossary of terminology and explanations of the terminology; so much so, that the first 100 pages or so could be more or less ignored for anyone who just wants to get on and use the software without being too bothered about, for instance, which datum is in use for their mapping.

__________________
Dave