I prefer many elements of the ET3 design. The problem is that it's not really moving. The 6% royalty is kind of ludicrous given the amount of work that's gone i

I prefer many elements of the ET3 design. The problem is that it's not really moving. The 6% royalty is kind of ludicrous given the amount of work that's gone into it - if someone made a single line then ET3 would get billions of dollars. I have talked to Daryl Oster several times and think he is a great guy and really honest advocate of the ET3 system, but I think the ET3 membership model probably isn't encouraging 'big business' participation, and the patent (while probably not that hard to work around) could be reducing interest from other areas. That said, I don't know what stage things are at in China. There was certainly some active research there. Another big benefit of an ET3 type system that you don't mention is the tube fill factor. In ET3 you can take up basically the whole tube, because there's so little air that you don't need to worry about the Kantrowitz limit (I think). In Hyperloop, you can only take up 30%. This means that ET3 can either have much smaller tubes (big cost saving) or much larger capsules (same cost... but TOILETS!!! ;-)).