I am considering upgrading to the late 2013 iMac 27" and having it fully maxed out. The i7 3.5GHz and GTX 780M graphics seem as if they would be hot components and in need of aggressive fan cooling. For anyone out there who has this model configuration, can you tell me from your experience how loud / quiet the fans are? Under heavy load are they obtrusive? What are your impressions of the overall acoustics? Thanks.