Musically different yes but also the people attending will be very different, afterlife will be 90% real clubber that come for the music and to enjoy themselves, ITD too but also lots of vip that don't have a clue about what kind of music will be play , about who's playing and also many tourist that will come to see the club once but who don't have interest on that night in particular and are there just to say we have been to HI !
Don't say by any mean that the lineup of ITD are bad , but due to his location it may not attract the same party crowds as if it was in another club for example !
So for me if you want to enjoy the music with other people that are there for the same reason = AFTERLIFE ALL THE WAY for me