Those are 2 champions that are very hard to compare.
But I would say Zed is the better pick in general.
He can fit well in more team compositions and he does well in a lot of matchups. Aurelion Sol is also good, but it is a lot harder to get the most out of him.
Depends. Zed can carry the game if played correctly, but so can Aurelion. Depends more on what you like, I'd personally go with Zed since he has high burst damage, but it really depends on who you are playing against (i'm presuming we are talking about mid, no?.
But I would say Zed is the better pick in general.
He can fit well in more team compositions and he does well in a lot of matchups.
Aurelion Sol is also good, but it is a lot harder to get the most out of him.
Of course they have very different roles so you can't compare them directly.