I couldn’t discuss the merits of any of the designs or technology, too far above my pay grade. But I will say that Musk seems to be much more involved in the project personally. Much more experience with building things in general. Bezos doesn’t seem to come in the top 5 - behind Musk, and the Virgin Galactic guy, and NASA, and the defense contractors... Sure he could throw endless money at it. But he doesn’t seem personally invested in it at all from my POV.
Of course he can underbid. When funding problems come up down the road, he doesn’t have a problem, NASA has the problem.
Musk is an engineer. Bezos is not.