Brightline also does not have a speed mandate forcing 200+ mph wherever possible. They can accept speeds under 100 mph for extended distances (e.g. climbing Cajon and Mountain Pass) and still beat weekend freeway traffic speeds between R.C. and Vegas. Of course, they will also have to accept that, during off-peak times, some vehicles on the freeway surrounding the tracks will pass the trains (I've seen plenty of cars and pickup trucks on I-15 approaching 100 mph, uphill on Cajon on a weekday morning, while dipping in and out of the truck lanes at 70-75 in my old Prius to stay out of the way).

CAHSR otoh, because of the travel time mandate in The Proposition based on competing with air travel SFO-LAX (which is dumb - competing with driving time, not air, is the appropriate bogey in the US), CAHSR has to use essentially Chinese, not European, track engineering. Unfortunately, that costs Really Stupid Money, which only an empire like China can actually afford. If CAHSR has something like a 4-5 hour end-to-end target rather than <3, it wouldcould look a lot more like Brightline.