I have the HHP8 Set with the Amtrak cars. The set came with 048 fasttrak curves. I also bought the MTH ones around the same time and attached photos of both side by side. Both cars measure around 18 1/2 inches. MTH has more details with the vestibule. Lionel's windows are smaller, but I liked the details inside. I use both cars and run them as two different trains. I am looking forward to seeing what improvement Lional and Atlas will make to their models.