I gave several sets of grandchildren the "Pennsylvania Flyer" set. All have used it to set up Christmas layouts, running a few times a week for a few minutes. But one MIGHT be a future train hobbyist- he runs it often, for the whole time the set is up. He also has added cars to the train, probably doubling the weight of the set trains meager 4 cars.
That particular engine got through two seasons, then at the beginning of the third- the locomotive started making noises (which to my son) sounded like gear noise. He opened it up and found good lubrication. So, I ordered a Pennsylvania Lion Chief Plus (6-82968) Pacific engine which cost about 1-1/2 times the set. No problem, he has been running that now for two Christmas seasons.
I inherited the set engine. The growling noise turned out to be a failing motor. That (I think)- is a main difference in the set engines- a tiny motor. Since, I replaced the motor, and added diodes in the motor leads to make it run more controllably, and it still runs as a switcher on my layout.
