Jinx's ult should have a CD reminiscent of Shen's ult.
Why, you might ask, do I bring up this topic? I make this argument because too often Jinx will toss her ult out and execute defenseless ponies after team fights. Do we really want tons of dead ponies? That's what I thought.
Really, though, I don't think having an execute that you can throw across the map about every forty five seconds to a minute and a half is very fair, considering Shen's global shield/teleport, which imo would be considered a counterplay to that ult, has a considerably longer cooldown.