It's now 26 April and I installed V28 last week. Been checking it out since. Syncing bookmarks now seems to work well (at least with Opera mini on my iPhone). Thanks Opera - you may well have the best browser now.
However, a small issue now remains - how to backup bookmarks. I cannot find a backup option on any drop down menu. Are we to assume that Opera link is now considered the preferred backup - or did I miss something?

Lack of sync feature is very frustrating. After using Opera for a long time, I deinstalled it 6 months ago as I got fedup with waiting for a version where Opera link worked. I installed Firefox instead. Recently I read a great review of v26 on CNET, so I decided to give it a try again. Well that was a waste of time, Opera Link still does not work. I have a sneaking feeling it never will. It is a real shame as my first choice would be Opera for all the other reasons. However, lack of sync is not acceptable.