I had 1st & 2nd run dockyard 38cl, also the first run of garratts, way back in the 60's. The 38's were mixed bags, with the 2nd run being slightly better detail wise more in regard to the stack, dome & sandbox being much lower & better scale, however it ran poorely with the motor & wheels binding. The 1st run was a beautiful free & smooth running model, tried without success to swap boilers around but on sold them several years later.
The garret was hopeless & was constantly providing problems no matter which direction it ran with wheels & valve gear binding, I forget how many times the model was fixed with time & money spent on it, luckily I was able to sell the model for $1150,00 privately which gave me air fares to China to visit real steam in operation there. The purchaser was a collector & more content with getting one of the first run garratts for display, which really was all it was suitable for.
So far I have not had any problems with operating any of the Plastic models, which includes 4xAusrains 36, on from first run, an Austrains 35. TOR 32, 42 & 44. A Eureka garratt waiting for sound to be installed after a full boiler unit being replaced. I do have a 40cl on order, but who knows when that will come & its abilities.
I also have 4 DJH models completed without sound & decoders, they will each be fitted with future TCS wow sound decoders depending on how the fitting to a 59cl goes, also one other DJH kit of a 53 under construction.
For mine the jury is out on the Chinese models at the moment, especially as we wait to see the quality in detail but more especially in the mechanical side of things owing to most of them using new factories, thus they will get a fair bit of scrutiny as they come out.