Don't leave home without it. I can only think it ill be invaluable for any interior shots. I was mad at myself for going to the UK without a fast, wide zoom like a 17-55 f2.8. If I had had the 6D with me, the 24-105 f4 would have been just fine. As it was I got by with that lens, but there were many shots I didn't take just because I needed 6400 ISO or higher to get them and I knew it would be a lost cause with the 7D.