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If anybody is thinking of having a bash at this round, after having done it in an anti-clockwise direction, I would definitely recommend a clockwise direction!
I think the mental sucker punch of descending down to Loch Mullardoch head seemingly 'half-way round' only to realise you've still got 60% (or more) of the way to go was a bit disheartening... Also, the actual terrain along the south side is, or at least felt, far more up and down and at times was really energy sapping.
I should point out as well that if there's been quite a bit of rain, the crossing of burn to go from the north to south side will be very tricky - with very few places to cross without getting wet. Go with some rubble sacks - or just be prepared to take your booties and socks off to make the crossing (unless you don't mind getting wet that is!). To cross and be guaranteed to stay dry (if there has been rain), you need to work your way upstream and cross, probably at the 300m mark across a vehicle track. You'd be able to pick up this vehicle track easier too coming down from Creag a' Choir Aird NW - whereas trying to pick this up down very boggy slopes from Meall Shuas would be trickier.
While I've read other reports that starting on vehicle tracks (going up Carn nan Gobhar) is better and you then have a soft bound down on heather coming down from Toll Creagach - I would say that after a long round, it's much better to be coming down on vehicle tracks. Also, the going down from Toll Creagach (as you near the 'path' that is marked on most maps) is very very boggy and the path almost doesn't exist.
Then, as you appear out on the side of the dam, you realise there's no way to get to the car park from this side of the dam so a (at the time) long plod around and back up to the dam/car park is brutal at this stage.
Lastly, there is no easy escape route if you are doing the south side last. At least if you were struggling, there's a much easier north loch path - whereas this doesn't generally exist on the south side.
So, going clockwise - you get the the boggy and mostly pathless ascent up to Toll Creagach out the way while you're still fresh... you get the most energy sapping up and down section out the way during the 'first half'... once you descend to Loch Mullardoch you only have 40% of the way to go - and then when you descend off Carn nan Gobhar it's very easy underfoot and you'll feel that you're back at the car sooner (once you're by the dam)!
Anyways, there are plenty of accounts of this round of 12 now - and many with far better pictures than me (as from Munro 6 onwards the mist shrouded every remaining top sadly), so I'm just throwing this account out there to give my opinion of the best way to go round!

the journey starts
parking at the dam - an early start!
walking round the dam
walking along the vehicle track
the vehicle track takes you quite a way up Carn nan Gobhar
views back down to the loch
Carn nan Gobhar summit
view of Sgurr nan Clachan Geala and Creag a' Chaorainn from Carn nan Gobhar
rock on
heading up Sgurr na Lapaich
looking back to Carn nan Gobhar
last climb up Sgurr na Lapaich
Sgurr na Lapaich summit
wonderful summit views
heading onwards to An Riabhachan
An Riabhachan summit
heading towards An Socach
last push up An Socach
An Socach summit
the ridge along to Meall Shuas and the route of its slope
heading down Meall Shuas looking ahead to Mullach na Dheiragain
heading up the very boggy path to Mullach na Dheiragain views down Loch Mullardoch
Mullach na Dheiragain summit
heading up Sgurr nan Ceathramhnan
looking back to Sgurr nan Ceathramhnan
last push up Sgurr nan Ceathramhnan
Sgurr nan Ceathramhnan summit
looking back up to the now clear Sgurr nan Ceathramhnan summit...
plodding on to An Socach
An Socach summit
the route up to Mam Sodhail
the final approach up Mam Sodhail
view to Loch Affirc between Mullach Cadha Rainich and An Tudair
Misty Mam Sodhail summit
the mist was well and truly in now - en route to Beinn Fhionnlaidh
another misty top - Beinn Fhionnlaidh summit
more mist on Carn Eighe summit
passing interesting rocsk onwards to Tom a' Choinnich
onwards with the up and down route
a brief clear(ish) spell
Tom a' Choinnich summit
summit selfie
onwards to Toll Creagach
the final strecth up to Toll Creagach
Toll Creagach summit cairns
Toll Creagach summit cairns
the sort of suggested route down from Toll Creagach
the plod back around to the car park at the dam