Contact List Management

I seem to have spent quite a lot of time over the last three or four years battling with my contact lists to keep them synced, current and de-duplicated. The root cause of the problem is that I want my contact information to be available in lots of places - phone, tablet, work mail client, home mail client, home laptop address book etc. - so that I always have access to it. This is a fine and noble goal but there are a few issues keeping me from my Contact Nirvana.

Firstly, I have three cloud contact providers, all of which I want to use, for one reason or another: Gmail (home email), iCloud (non-email purposes) and Exchange (work email). Three-way syncing and de-duplicating is non-trivial, especially when each service assumes it the definitive source.

Secondly, my home laptop doesn't want to sync Contact information from my work Exchange server. The problem seems to be that Outlook/Exchange use a number of different address books and the OS X address book doesn't sync with the right one, so no contact information is downloaded (there's bound to be a way to fix this but so far it remains hidden in the noise at the Microsoft/Apple border).
Finally, all three services have "features" and idiosyncrasies which prevent them playing nicely together (probably for sound commercial reasons) and make contact management more difficult than is strictly necessary.

I could sort this out by hand (download each address book to Excel or Numbers, normalise the fields, de-duplicate the entries then upload a new list to each service) but this solution is prone to errors, takes a long time and needs to be done regularly to keep the three lists in sync; awkward.

It would be nice to define one service as the master and slave the other two to it so that updates to the master propagated down to the slaves. Nice, but not currently possible (see comments about idiosyncrasies, above).

There might be a solution amongst the third-party contact management systems (Xobni, for example) but they all cost money and there's no way of knowing if they will do the job; risky.
If the APIs for these services are publicly available (assuming they exist) it might be possible to build an app that queried one service and updated a second, de-duplicating as it goes. Possible, maybe, but this is not a quick or easy solution.

My only realistic solution, as far as I can see, is to scour the Internet in the hope of finding someone who has not only suffered from the same problem but has had the time and energy to build and document a solution. Such a person would surely be lauded across the land, as indeed would anyone who could identify such a person and make their achievements more widely known. So far, my efforts in this direction have not met with significant success but I'll keep trying; updates to follow, probably.