I have an A class with a Hornby class 52 chassis (see video above), but it moves like a rusty door hinge and I'm feed up with its poor running quality. The "2ft rule" may help hiding lack of scale detail on some models, but the "2ft rule" cannot hide poor low speed running, not from any viewing distance. It's awful shunting.
Has anybody managed to successfully fit an RTR centre drive chassis into an A class such as Richie's suggestion of an Altas RSD4/5 or other Bachmann, newer Hornby, Athearn, etc, and if so did it run well at crawl speeds?