I support Shockproof with immunity to full paralysis instead of the speed drop (for the same reasons as Deck Knight stated).
Being able to reliably absorb paralysis is a greater advantage than keeping a high speed. Yes, being able to outspeed things is nice, but Pokemon like Gengar (with max speed), Azelf and Jolteon can cause a lot of damage to CAP11, who cannot outspeed any of them, having moves fail with the 25% chance of full paralysis can be very dangerous. And CAP11 can bypass the speed drop with Sucker Punch/Mach Punch/Vacuum Wave or even use it as an advantage with payback.
Being able to reliably absorb paralysis is a greater advantage than keeping a high speed. Yes, being able to outspeed things is nice, but Pokemon like Gengar (with max speed), Azelf and Jolteon can cause a lot of damage to CAP11, who cannot outspeed any of them, having moves fail with the 25% chance of full paralysis can be very dangerous. And CAP11 can bypass the speed drop with Sucker Punch/Mach Punch/Vacuum Wave or even use it as an advantage with payback.