I just purchased some new Lionel locomotives (including the new LionChief Plus 2.0 F3's) and I love them! The plastic clamshell that holds the locomotives certainly does it's job and everything was in very good shape when I opened it up.
I also collect Marklin HO and noticed Lionel's' new plastic clamshell is identical to what Marklin began using a number of years ago. Apart from being a little bit of a challenge to repackage the locomotive, I find the plastic clamshell discolors and becomes brittle with age. By contrast, I have much older Marklin and MPC Styrofoam packaging that is still in very good shape.