But do I not need that to do a responsive site??
I highly recommend this thread:
It gets very interesting from answer No.8 and further down.
I still believe, it would be very nice from ADOBE to keep to this statements.
This helps a lot for almost any case and for your question.
you´ll find his ( Pavel Homeriki ) answers as well.
Should your site be adaptive (separate layouts for each device) or responsive?
Hope this helps