My B&O, C&O, UP, Wabash and Silver Flash PA's all held up quite well at train shows running on AM track. The only one I had trouble with was the WP set and that was because of the metal couplers (which I didn't realize at the time) on the passenger cars shorting out the set as the coatings wore off. Otherwise, even the WP PA's ran well.
I'll admit, my MP's are coffee grinders and I never used them at a show.
Rusty