they are both pretty much the same... the johnson control is a little smaller.

what i would do is but a johnson control ($75) for the warm side so you can get the temps EXACTLY where you want them. then buy a cheap zoo med 500r ($25-30) for the cool side since theres a little more room for error. or you can just two johnsons or rancos.

and yes flexwatt is a UTH it is just thinner, you can buy it by the foot, and it comes in different sizes (3,4,11").