If I were to start over in the hobby, like a newborn babe with no knowledge and no history, I would probably still buy a lot of traditional, given the realistic constraints of space and budget. But I would focus on MTH: I keep seeing all these neat MTH products based on Midwestern prototypes, which I perceive as a chronically weak area for Lionel.
But I am not a newborn babe with no knowledge. I am someone who played with his dad's train as a kid; someone who long ago fell in love with the traditional train "look," with Pullmor motors and ozone, with the feeling of mastery when you coax out a realistic slow start by working the transformer handle just so, with trains whose insides are big and brutal enough to evoke just a little bit of the real thing represented by their outsides, with trains whose bells and whistles are actual bells and whistles. So, given my history, were I to start over, I would do just what I am doing now--collecting old Lionel! The ONLY doubt I MIGHT have would be whether Postwar Flyer could scratch that same itch...oh! those MoPac PAs!