IMHO EL-S has lower throw angle than EL-P. In general, it is easier to play with EL-P as EL-S feels much, much harder. With EL-P it is easier to block and loop if you don't hit hard. For me the advantage of EL-S is its stability in counterlooping rallies. If EL-P was as stable in that component, I would not change to EL-S and that is why I still keep it on my BH. EL-S is like a tacky, hard Chinese rubber: you either commit to the shot and get it, or put the ball into the net. I cannot measure the spin with my eyes, but it feels like EL-S has more spin when applying lots of power, and less with less power.
I played with a massively worn out FX-P for 15 minutes and can't say much that it felt superslow to me, though the arc of topspin looked great.
PS. Interestingly my first sheet of EL-S (MAX sponge) felt very close to EL-P, while the second one (again MAX) felt very different, much harder.