I think Trump would be an absolute disaster in both domestic and foreign policy but he really couldn't do anything with Congress united against him so he would be forced to compromise.
Cruz on the other hand and bat shit crazy fundie who truly believe in End Times and all that other horseshit and he's the last guy (out of the entire field of Dems and Repubs) that I would want in the office. Also he's whiny humorless bitch. There is a reason everyone who has ever had to work with him hates the guy.