This is a choice ur going to have to make yourself, basically the 12-24 can act as a walk around lens while the 11-16 would be more specialized. I have no problem shooting someone with a distance at 24mm but at 16 the same person would look as if they have humongous shoulders or massive noses, 24mm isn't too bad. This means u can keep the 12-24 on while going in to a building, trying to get a sweet sunset and even when trying to snap a pic of your girlfriend. If you try that with a 11-16 she'll complain she looks fat. I would love to hav the 11-16 I can definately see myself using it at 2,8 indoors especially in churches. My 10-20 is AWEFUL wide open but at f8 it's not bad and I don't want to upgrade as I would rather save for FF and get a 16-35 instead.