Immigration and TPA are two pretty good places where we can accuse Cruz of being loyal to his donors, even if he panders further right than Rubio or Jeb Bush are willing to do. The fact Cruz has been telling media outlets that mass legalization of illegals isn't off the table, while railing about amnesty to conservative audiences, should take the shine off his armor to normal thinking folks.
There's some truth in what you say, Cruz is on the wrong side with TPP/TPA and he has said some contradictory things abaout immigration. However, Donald Trump has hardly been a model of consistency in his stated political beliefs either. The bottom line is that there aren't any perfect candidates, but I put both Cruz and Trump light years ahead of Jeb and Rubio.