The models are similar, with the 38041 being most accurate I believe, experts will chime in.
These two models are the best detailed and most accurate hudsons Lionel has ever produced.
The sounds are superior in these two models when compared to the 1990 version. However, while 2 chuffs per driver revolution is an improvement over the 1 of your 1990, the prototype has 4.
The Pittman can motor in the newer models offers far better slow speed performance and is equipped with cruise so the Loco with hold its set speed unlike the 1990. These j3a's use a similar puffer style smoke unit as the older model.
Here are videos of each,( not mine) Class lights , whistle tone, and driver type are really the only differences.
Heres the 38041 in action: ( my personal favorite, wish Lionel would make one with Legacy)
Heres the 28072:
