Going Spare, i was 12 then. I had 2 of their own controllers, but when they aged, my local club, put me on to H&M. I have just tried my Dutchess of Athol, on GM, then Duette, pulls away much quicker on Duette, and is in my view, more responsive, will slow run, and pull away , much better On the later HD, Bristol Castle, with Ringfield motor, its not so noticeable. Most of my 23 , 3 rail locos, have old motors. I have a Dodds, Magnifier, and have re magged, (or similar), 5 of these. It makes no difference. Could also be that these locos are so much heavier than modern ones.