The Tiger doesn't have a metal lower hull, although it does have a metal "tub", so it's as durable as a tank with a metal lower hull. The Tiger is an older model, but it's just as good as the newer Tamiya tanks, like the Panzer IV and the KV-1. It's even much better OOB than the newer Panther.

The model with the best sound is the Leopard 2A6. But it's a modern tank, so I guess the best sounds has to go to the KV-1. I like the startup sound of the Panzer IV, but the rest of its sound way too much like the King Tiger, Tiger, Jagdpanther, and Panther.

All of them comes with plastic tracks. The only Tamiya tanks that have metal tracks are the older Sherman models, and the Leopard 1 and the Flakpanzer (forgot its name). The only models that NEEDS track upgrades are the King Tiger and Panther. The rest does not need metal tracks, but they will run better and look better with one.