Of the two I expect the arid desert world would actually have much more usable land than the ocean world - there'd be patches of moist climate around each of the seas covering a lot more area than the seas themselves. Also we'd be able to expand the habitable areas via irrigation and other such techniques. And it'd be much easier to access the mineral resources in a vast desert than it would if they're on an ocean floor. Both planets would probably have very harsh weather, but I suspect sandstorms would be more survivable than super-powerful hurricanes.

The 1% sea planet has nothing to prevent the population from killing itself. At some point, you will run out of water. You can't stretch it out indefinitely. Seeing as water is essential to life, gimmie the planet with all water. I'll make floating land masses.

They would both suck logistically. Thus I choose mostly water, simply because it is cooler.

There would still be rain on the arid planet, just not in most places. I don't see how the world would "run out" of water - there just wouldn't be a lot of it in circulation at any given time.

Following Darwin's theory of Evolution, we'd all still be fishies in the sea. Better happy guppies, than thirsty dumb primapes, I say. Under the sea! *Queue musical number.*

according to that logic, we evolve to be like nautolans on the water planet, or jawa and tusken raiders on the desert planet.