I checked all the Face2face books from starter to the upper intermediate and i actually worked with the intermediate and i think it could help as a self study book but not for an English course because if you worked with it in every level you wouldn't notice a big difference in your English skills , you will only get to know new vocabulary which could happen by reading any book actually. so i don't think it's as strong as i expected for someone who already read English books and watch movies without subtitle.