Hi, thanks for replies.
My edit attempt was on iMac computer. I didn't try to edit on phone. Not to worry: that's a very minor issue.
Re email accounts
A per the way that Apple seems to be working, my email accounts are using both systems.
My main Apple ID addresses are on iCloud, and they were transferred some time ago in line with the Apple transition scheme/timetable,
My additional MobileMe email accounts are still on MobileMe. You will tremember that Mobile Me allowed and encouraged multiple paid email accounts under any one Apple ID. Apple says that those accounts will transition at the end of June. So the answer is not which one, one or the other, but both - because that's how Apple is operating and yes it can lead to confusion. Of course I would prefer if all the accounts would run the same way and all operate on iCloud. At the moment, it seems that it is only the main Apple ID account addresses/identities that function with iCloud.
Maybe there is a way to transition all Mobile Me accounts now, which I have missed? It doesn't seem to be in System Prefs though. Systems pref is only interested in the main Mobile Me accounts – which are, to confirm, upgraded to iCloud. That may be what you mean by 'switch off in System Prefs'. As I was noting, there doesn't seem to be a way to manually manage the additional MM email accounts. We have to wait for Apple to do it automatically, in their own time. ??
iCloud Prefs does have a 'manage' option, but it doesn't enable you to manage anything much. You can buy more storage, but I have the max amount anyway.
Mail Prefs doesn't allow anything much either, apart from adding new accounts. MobileMe accounts cannot be changed to iCloud accounts there. They all appear there and run simutaneously. The options for accounts that Apple gives are: iCloud, MobileMe, Microsoft Exchange, GMail, Yahoo, AOL and Other. It is not a black and white matter of only one OR the other.
Mail and Gmail do work together, or should. Gmail is of course set up primarily with Google, but Apple Mail DOES also, of course, allow Gmail accounts and others to be set up in Mail. It even ofers an automatic setup for GMail specifically (although this may also be set up under their IMAP or their Exchange 'templates).
That's the bit I was referring to under 'Mail and Gmail working together, or not'.
The iCloud and Gmail/Google apps sync is a wider issue. I see that some people have found some sort of more or less workable solutions to sync the two, but generally it looks like less, rather than more. That's why I say that unfortunately it may be time to totally migrate to Google, after sticking with Apple apps throuhgh thick & thin for the past 18 years. If Google and iCloud won't sync reliably across mail, contacts and calendars, it's a dead loss. For goodness sakes, I have just ordered a Mini Lion Server, so that I could better manage the sharing of Apple's mail, contacts and calendars, but now that may be redundant.