The most important issue in terms of long-term cost-effectiveness is how much it will actually be used, and how much of the time it is actually full. High Speed Rails or any trains for that matter, are plagued by the inefficiency of having to run at a set schedule regardless of how many tickets are sold, and they ultimately don't justify their own existence in most of America. The hyperloop, aside from attracting new people who otherwise wouldn't have considered rail travel, also has the benefit of having smaller capacity and being able to adapt to demand more quickly. With no stops between SF and LA, if there are no passengers at a certain time, you just don't send the vehicle -its that simple.