ERF-NGC-European:
Re Mercs - like everything to do with Manufacturers and certain models there are strands of development to like or not to like. I can honestly say that the last really good Merc I drove was on a Y-plate and was a 4x2 tractive NG-1633 unit and that was a terrific motor - pleasant to drive and torquey. It was a real flier! But it still had the ZF Eco-split crap synchro box in it.0
And then came the horrible EPS SK-cabbed Mercs which I hated (the only lorries I’ve ever hated!) but even then - back to strands of development again - the Merc SK 1850 I drove to Fez in Morocco and back for an O/D in hospital, had the SK Euroliner high cab and 500 horses. It was a serious ‘uphill-downhill’ V8 machine in the Spanish mountains.
Then along came the Acking F**cktross and I drove some early LHD examples of those horrible machines. Cab wasn’t bad but the Iveco was much better. ‘Telegent’ gearing was not to my liking. But again that’s a bit subjective, given that the Twin-Splitter appointed Eurostar I drove after it was not to everyone’s taste but I preferred it.
The 1633 a with Fuller option might have been a game changer Robert.
I can say that a DAF 3300 with a 9 speed Fuller was one of the best trucks that DAF ever made… by mistake, that was meant to be a 2800 ATI and we got it. 
I think DAF also seemed to have maintained their composure longer and better than Merc ?.