Generally i liked the fifth season, but i think people think its a bit deeper than it actually is. I find le guin to be a bit more nuanced and leave you thinking a bit more. The fifth season felt a bit more: evil people are obviously evil. The other side is i think jemisin has better developed characters than le guin. A lot of le guin (much like a lot of older scifi) feel very much like idea books where character development & plotting came second.
If you like those two authors, i would really reccomend Octavia Butler, who i think is a bit similar but better than both (lets see if i start a flamewar ;)