After three Canon cameras 850, 450D and 700D, took the plunge and went for full frame. Results so far have been superb though confined to portraits and landscapes. The jury is still out on the 24-105mm zoom lens that came with it. I have been using a 50mm f1.4 USM lens for most of the photos which has produced crystal clear images. I have also tried out my old 70-300 IS USM lens and have not been overjoyed with results. The 100-400 L zoom lens appears attractive but am concerned about the weight - my bag already seems to weigh a ton!