It’s your oil. It’s the only thing which changes so much from hot to cold, a hydraulic cylinder will be faulty hot or cold.
I tried the Castrol Syntrans/Transmax too, still notchy from cold, drained it off after a month and threw it away. Total waste of time and money.
That’s when I started talking to experts in gearbox design & rebuild, Motorsport engineers etc and went on a journey of discovery.
Never looked back 
Quick update:
Slave cylinder changed. Pedal feels much better. Cold changes into 2nd are much improved. 1st not so much, but that’s only really when it’s cold and the vehicle is in motion. Warm changes do feel better as well but they were never an issue.
Overall it was worth doing, but there is likely still room for improvement even if they are incremental.
Will put some more miles on it and go from there.
I’m another to vouch for DuratacNC’s gear oil formulation, on my 2006 NC with 75,000 on the odo.
I was suffering from a bit of a notchy change in the low gears, and what I can only describe as a slight ‘catch’ going from 2nd to 3rd. I’d already raised the clutch bite point some time ago.
Last week I opened up the centre housing to check the points mentioned on several forum threads.
The selector plate had a small amount of wear in the usual place but I thought not enough to need replacing. I topped up the turret oil; There was no oil visible but the business end of the gearstick had a coating so not totally dry. The ball had a smidgeon of grease so I gave it a new dollop. I also refilled the gearbox with DuratecNC’s formula.
From the off the gear changes felt slicker in all gears going up and down through the box and this has only got better in the hundred or so miles I’ve done since. The ‘catch’ I mentioned slowly went too. (DuratecNC’s explanation of delayed effect is the time it takes to re-coat the cogs and synchro with the new oil.) I’ve yet to experience a start on a frosty day as we haven’t had one since, but I’d say what I’ve experienced after the topping up and oil change was well worth the few quid and afternoon’s work it took.
Clutch / brake fluid change in on my ‘list of things to do in the near future’.
I’ve just completed my 2nd change after using DuratecNC’s flushing oil. A noticeable improvement in required effort for going into 2nd with the flushing oil inside after a few miles. Now have the long term stuff in and it shifts lovely.
You need to release the clutch while in neutral for a full double declutch, and also blip the throttle when changing down.
I entirely agree. I have a 3.75 and that also has a USB socket and 3.5mm audio jack at the rear of the cup holders and its connector needs to be disconnected as well.
Since I did mine, I have seen a video on YouTube that shows (certainly on the later cars) that the whole section with the window switches can be prised out separately to make removing that connector much easier.
I also found it quite tricky to lift the nylon cable tie off the bolt, even with a pair of circlip pliers. They are cheap enough, so it might be easier with two pairs, one on each tang.
@McTrucky Thanks for this fantastic write up; the pictures really help. However, pay careful attention when removing the gaiter. If you find an (ali)gator, you’ve got bigger problems 
One more vote for DuratecNC’s gearbox oil. I have a 2.0 sport 2006 NC with 57k up, terrible notchy gearbox from cold, replaced with the special formulation from DuratecNC and problem solved. Really smooth straight out of service. Very happy customer.
Update - flushing through and bleeding the clutch circuit restored the bite point and lightened pedal action. What a transformation!
Thanks all for inputs.