Cruz wins easily, but loses the GE handily regardless of it being Bernie [more popular policies and obviously more likable, just look at how the debate went] or Hillary [who is somehow less artificial and robotic in comparison to Cruz].
Cruz smashed Sanders. All the polls immediately after the debate showed Cruz crushing him, until the Bernie Bros blindly voted that Sanders won.
As for the Republican nomination, I'm inclined to say Rubio only because Cruz thrived off of anti-Trump conservatives. Rubio was the rising star, and probably would've won New Hampshire, then South Carolina, and probably a good chunk of Super Tuesday states. The primaries probably would've been Rubio vs. Cruz vs. Paul.