Reckon I have it 99% clear now thanks. Based on the help here and elsewhere plus some further methodical study, here's my attempt at a summary:
With the exception of Samples, My Clippings, and some other specialised
content (including Subscriptions, but there may be others, such as Blogs?
Newspapers?),
all titles will appear
in total on both devices after using Sync. But the
split between Home Screen and Archived will not necessarily be the same.
In particular, a book 'purchased' on either the PC, iPad or Kindle, will
appear automagically on both devices. (Including free books.)
I'm now just one item away from reconciling my comparison, but hope to sort that soon!
Code:
NO. of TITLES
SOURCE Total Home Archived
Manage (on PC) 21
iPad 21 9 12 (But yet to check they are SAME 21.)
Kindle 27 11 16
After excluding 2 Samples, My Clippings and 2 from non-Amazon sources
('MobileRead' and 'MobileReference') that becomes
Kindle 22 6 16
--
Terry, East Grinstead, UK