This lens is my standard lens when I am just doing some walking around photography. The focal range is great and it makes for a great all around lens. However, it isn’t small, weighing in at a couple pounds, but the quality is superb. I purchased this lens, along with the Nikon D3, when I knew I was going to be working in the lowlight environment of the Costa Rican cloud forests in Monteverde. The extra few stops and incredible quality was several steps above the 24-120mm lens that I also own.
On the wide end, especially on a full frame camera, the 24mm is wide and very versatile. It isn’t an ultra wide but it does provide enough coverage that I can get in close and still show a lot of the environment behind the subject. There are definitely times that I wish for a little bit longer lens but when that happens, I switch to the 70-200mm.
Ultimately, it comes down to this. If you want a fast and sharp lens but can sacrifice some weight than this is the lens for you. If you want a one lens setup and you can sacrifice a tiny bit of quality but gain a lot of versatility, then go for the 24-120mm. I use them both and the situation dictates which lens is mounted on the camera.