At best sony will cut the load time to half?
Right now things are on standard HDD, and the loading times are not bad, typically in the sub 30s range, SDDs in general will already cut that in half. So Sony might have the advantage of 5-6s loading time?
For next gen titles with larger assets there may be a large difference, maybe 10 extra seconds? Oh no
Better SSD is definitely nice to have, and there will be a tangible difference between the consoles.
As for 4K 60 FPS, Xbox will have the edge there. It's unclear to me whether the power budget they gave to the PS5 will keep it cool. If the PS5 sounds like the jet engine PS4 Pro, that's quite annoying. Your 3D audio will be supplemented by jet engine audio unless you turn up the sound pretty high (or wear headphones). Towards the later stages of console life, the PS5 and XSX will likely behave like the OG PS4 and Xbox One, where the one struggled quite a bit. But, by that point they will release new consoles, likely with better everything, so these points will be moot.
At the end of the day, the smart move is the following:
1) Wait to see the noise and heat levels of the consoles, making sure there are no glaring flaws (like a RROD scenario or jet engine fan performance)
2) Buy the console that has your favorite games on it
The only way I see PS5 falling behind is if they launch at an equivalent or higher price. If they launch at a lower price (by say even $50), they will still be quite a bit ahead.
Personally because I play multiplatform, I would buy the console that has more longevity built into it. Sony exclusives generally do nothing for me, especially since they ruined things I used to love like GoW.