I went with Numenera because it just has a better presentation and feel to it.
Star Wars looks cartoonish compared to past Star Wars books, but also has a vibe similar to some WotC products. I think they should have taken the time and created something truly unique and establish their own presentation of how Star Wars looks.
Shadowrun and 13th Age are just too busy and crowded. What I am seeing is a segment of a story but there is so much going on that I don't know what's really going on beyond the scene. While provocative they don't pull me in and make you want to learn about the world around them; I am interested in learning about the characters and why they are fighting, but that's it.
Numenera, on the other hand, has that classic sci-fi feel to it like I'm looking at a Frank Herbert or Edgar Rice Burroughs cover. I can see representations of heroes, but I have a good view of the world on the cover that pulls me in and makes you want to learn more about what I am seeing. I want to explore that world, not just be a character in a story of that world. Which exploration is the key thing that Numenera is about and I think the cover captures that perfectly.