I returned all four sound cars I purchased. I do a lot of trackside railfanning and the sound of cars squealing as they roll by even when on a slight curve is part of the experience. I do not often hear banging and clanging in or about the cars. I certainly do not want to hear banging and clanging as the cars roll by on my model railroad. I want to hear the flange squeal. Some might prefer not to hear that. Fine. As I understand the sounds, the squealing occurs less frequently than the other sounds. Not for me. Why did I not try it first? I accept the Forumites' descriptions and I cannot expect to return a used car as new.
I have several sets of Vision reefers. Those sounds I like. I'll use those.
Lionel, do what Gunrunner John suggested. Better yet, include a sensor for the curves.
Scrapster