My limited experience of teflon-coated cables has been from removing cables of unknown history from a second-hand bike and discovering a patchily-coated steel cable in otherwise pristine condition, and a whole load of teflon dust. On that basis I've mentally filed them somewhere between "waste of time" and "okay for race mechanics".
Related: Experience has taught me that (given a quality outer with appropriate lining) lubricating new cables is an own-goal, as you're just introducing more stuff to gum up. Which isn't to say that a squirt of lubricant to flush the gunk out can't extend the life of a cable once it's starting to get a bit sticky, but new cables are best fitted dry. (A bit of grease to discourage water from entering the open end seems harmless, if inconclusively helpful.)