iostream vs. stdio

so, I've got EXPERT PROGRAMMERS telling me to use printf instead of cout in c++, ok but why? what is the difference (in b4 stream)

>>22
printf() in 64-bit and 128-bit environments would by necessity support outputting those sizes.

>>24
There's fwrite(), puts() and other output functions that don't do formatting if you don't need it. But most of the time you do need the formatting, and that's when something like "%08X-%08X-%c|%d/%d%%" in a single printf() is better than a whole bunch of setxxx() calls.