[Xixi]

I have an E-2 visa, valid for 5 years. The way it works is exactly as you read on www.uscis.gov: upon entry in the US there is a 2 year reentry permission: it is renewed each time the border is crossed. In practice it means that I need to go out of the US at least once every two years to keep the ability to travel freely. Conclusion: the E-2 visa is great if you intend to travel abroad often, otherwise another visa is probably better.

The durations may vary depending on the country the visa is issued from (due to the underlying treaty), and the status associated to it: in my case France as an essential employee (NOT as an investor).