Slightly? a lot longer with a lot of pop-in....and i mean a lot!
So the difference will be night and day.
not really. we saw that SSDs way below spec show zero load time difference. the worst you get is a 1 frame stutter for the worst ones.
this means that we have not yet seen how low you can actually go in terms of speed and still play it wither zero difference.
so if an SSD severely below the spec of the PS5 can play it with no difference in load times, that suggests that the game is currently limited by either CPU speed for loading or it pre-caches a lot of stuff into ram before transitions.
we have yet to find out how slow a drive can be until you see even the slightest drop in load speed in the game. seek times may help, but that would only mean that you would have to place important files close to eachother for fast seek times for transitions (which is what well optimised games do already)
I bet a decent HDD would see little to no load time issues if optimised for the seek times of an HDD (which it currently probably is not due to only targeting a system that requires an SSD)