My first team of 1 pally and 4 priests took me 17d 7h to lvl 70. This was before the 2.3 level speed change.
My second team of 1 priest and 4 warlocks took me 13d 5h to lvl 70. The change was during my levling period, think 2.3 hit when I was about 35-40
My third team of 5 shamans took me 9d4h (and 4weeks irl time) to lvl 70. This was after the 2.3 change.