You know fanboys are going to hold on to every millisecond. Extremely small loading time difference could be the new 400X zoom.
The stupid thing is that over a certain speed the perceivable time delay, at this point in technology anyway (and I must stress that part) is utterly pointless. This isn't something that you will see during normal gameplay, you wouldn't even notice it when assets are called. The only time it would matter is when shifting assets through memory, so in layman's terms your generic bog standard loading calls, and then it's absolutely minimal because it's theoretical minimum and maximum bounce about so wildly anyway.
In short, this is far more than enough for general use, and anything more is, dare i say it, a bit overkill... at least at THIS POINT IN TIME. As assets get much larger and much more complex, faster speeds will of course help. But even then, by the end of the generation many years from now, you will simply be looking at such a minimal speed increase that t won't matter at all, even in fringe edge cases.
What will matter, is GPU grunt and cpu power, and the jury is still out on these two for both machines. As it stands, there is more out there that the SX is better than the PS5, but that can change as easy as the weather depending on the "leaker".
But make no mistake about the SSD. I see some Sony fanboys creaming at the thought they may have a better one, and MS fanboys crying that it doesn't matter... this isn't the same situationas PS4 and xbox one. This isn't going to be some massive 900p to 1080p difference. This is minimal, at best, for asset calling and steaming into memory. You won't be walking through a level and a tree pops in. That's not how this works.
So from what i can see, speaking purely from what information is available, one company has spent a lot of cash on expensive SSD tech, and the other didnt... that will have some effect on the price of the console, and more importantly, the quality of components used in the console to hit a set price mark.