Referring to the UP #105 GP-7 with Legacy from a few years ago.
The loco has the random sound effect of the wheel rubbing on the rails which adds a lot of realism. I have two newer Legacy diesels that do not have this sound effect.
Also, this loco has a full lighting package as well with directional markers that change green-red (front and rear)
Mars light
strobe
I realize that other prototypes may not have had this but is Lionel scaling back on the features to hit a price point?