These are beautiful cars! My CGW version has been set out on the windowsill in the kitchen for weeks so that I can better appreciate this new favorite. My disappointments were their light weight; the "hollow" sound of a "loaded" car, echoing as it rolled by; and the solid, one piece trucks.
The light weight was resolved easily by adding adhesive backed tire weights at the locations on the floor, at the ends of the car, which are just the right size for that purpose. The "echo" was solved by simply drilling holes in the load shell, one at each end, then filling the shell with expanding foam insulation, cans of which are available at your local mercantile or Ace Hardware.
The trucks are certainly good looking but I prefer that the more authentic type in which the bolsters are free to move in the sideframes, meaning that the springs actually perform a function. Not fatal.
It would be great if Lionel would issue additional car numbers for the existing road names (especially CGW) and add CNW, MILW and UP, among others. Since I'm not aware of SIRT handling grain, I added Kadee couplers for use on my future MILW layout which is still very much in the dream stage.