The route Ruggtomcat and I took was;
Back roads to Ratho then Newbridge
Newbridge to Broxburn on A89 Edinburgh Road (not an NCN route, but fairly good pavement / on road lanes all the way) Although it's just alongside a busy main road, with nothing interesting to see beyond housing estates and industrial units.
Continued as far as Bathgate on this (although sections just on main road, it was reasonably quiet early in morning, think most traffic would be on M8)
We couldn't find the way onto the NCN75 route from the new Bathgate Station, which at the time was recently openened and there were no signs to the (at the time) unopened (but completed) replacement path. We followed bikehub directions for the "road replacement route" as best as possible as far as Armadale, as at the time there were no signs for the replacement route.
After Armadale we stumbled upon the completed NCN75 route, all freshly tarmacced and silky smooth - no signs up on it, but very definitely completed and ridable.
Note on the replacement NCN75 route - it is fairly flat on the map scale as it follows the railway line, but for a flat and straight route it twists and it turns as they havent bothered to level the ground, just followed the contours and curves of the moorland alongside the railway. It's also very, very exposed with no shelter, so was fairly unpleasant into the headwind. Route crosses and recrosses the railway on a number of occasions and there were quite a few forks and turnoffs that were not signed that we got lost exploring down.
Lost the path on a number of occassions in the villages, but seemed to pick it up by chance / luck / good fortune and eventually arrived in Airdrie at the Drumgelloch end.
From there 75 takes back streets and again made it through more by luck and chance than anything else (certainly not through helpful signage!)
It twists and turns all over the place in Coatbridge, through estates, parks, back roads, bits of cyclepath, old railway, pavements etc. Numerous occasions we missed the tiny signs because they obviously were put in from point of view of someone walking the route in one direction and not cycling it in other.
From Coatbridge it is quite main roads to Uddingston, a little bit more getting lost in parkland until the Clyde is picked up a little bit further on in Carmyle.
There was a diversion off the Clyde path at Dalmarnock which turned us out in the blasted wastelands around Celtic Park. Once more lady luck smiled upon us and we managed to regain the river after quite literally going round in circles in some half-demolished council estate for a bit. After that it was back on the clyde path all the way to SECC / central Glasgow.
The sections through Lanarkshire were quite literally carpetted in broken glass. Not just the odd broken bottle here and there, it was as if the local passtime was to simply smash as many buckie bottles on the path as possible. At times we got off and pushed, it was so bad you couldn't weave your way a route through.
Some of the parkland sections near the Clyde were also more akin to CX than gentle touring.
There's not really anything much to see on the route, the nicest bits were either alongside the Clyde or alongside the railway on the moorland. Beyond that it was run down towns and estates and decrepit footpaths. Seriously don't recommend it unless that's the sort of adventure you're after!