Many of us know that just about any Legacy steam loco will run well with any other Legacy tender coupled to it. Actually, the locos will run, soundless, perfectly without a tender. I often swap tenders and locos and I always run one of my locos - my Mallet, only with another (larger, so it looks appropriately sized) tender when I run it.
Anyway, I have a Vision 0-8-8-0 I bought used that has serious issues. I'm in the process of working through them one by one, when and if I can, e and have it so it now mostly navigates my layout well - at least a low speeds (all that seem appropriate for it anyway). This poor loco has seen some serious running/abuse and wobbles and randomly strays from the rails. Probalby not the best bargain I ever bought but its mine now . . .
In desperation, thinking maybe the tender-loco coupling height was mismatched and inhibiting the rear drivers from staying heavily on the track, I switched its tender out momentarily for one from a conventional Southern Atlantic 1910 (seemed like the right size and it was right there). Never swapped conventional to Legacy tender, but what the heh . . .
1) The loco ran better - it still has some remaining issues but it stays on the track better, confirming my diagnosis that the original tender coupling height was bad.
2) This PRR 0-8-8-0 now sounds like a really good diesel! All Legacy tender-to-Legacy-loco swaps I have done give me some sort of steam sound - maybe not the correct type (two cylinder instead of three, or four, etc.) but steam. I have only this one weird, if sort of fun!
Although it would be more fun if this 0-8-8-0 would behave better.