>Night and day difference in low >light conditions
>from my everyday lens Nikon 18-200mm VR. I'm >shooting with ISO 400 to 800 (in appose to ISO 3200) with much >nicer results.
Yes, a few stops can make a large difference. It can mean shooting at ISO 400 instead of 3200 and benefiting from the corresponding better image quality, or at 1/125 second instead of 1/15 second, and being able to rid of camera shake, or without a flash and therefore without harsh shadows.