this might be appropriate for NASA level programs, which i suspect are heavily spec'd and designed before any code is written, and then they want the code to work, probably without much iteration. i'm not sure if this is completely wise, since iteration on implementation can be useful, but if the client's specs don't change and you have very experienced coders, then iteration may not be that useful. very correct code is.

on the other hand, for (young) programmers learning the latest web 2.0 tools andtweaking if not changing the product frequently, iteration, and thus speed is incredibly useful.

i think both approaches, heavily simplified here, could work--assuming the folks involved aren't just following a recipe but engaging with the process and committed to making it work for their particular circumstance.