I'm really unsure about the author's assertions regarding the maximum accelerations that people can take. Those might be the normal regulatory limits for passenger rail, but I'm pretty sure that the accelerations I've experienced on planes have also gone up into territories the author would consider utterly unacceptable.

On the other hand, I think he has some good points regarding the cost numbers. If pylons have all the advantages that Musk claims then why aren't we all getting around city on monorails?