I've bleeted on about this in the past, but every time I remember to take the Nikon 16-35 VR on late evening walks it blows my mind.These are more or less just snapshots but are a good demonstrator - taken at about 9-10pm this evening, mostly at 1/4 second f/4 hand held and not a vibration in sight.
At 16mm I can get almost 100% sharp shots at 1/2 second, and about 20-30% perfectly sharp at 1 second!
The later ones were taken in complete darkness. The only problem is that white balance becomes a real ball ache as nothing is lit by ambient, so B&W conversion becomes tempting.
All in all my advice is that if you're thinking of getting one - do it. It's the ultimate evening lens. These images are significantly brighter than they were to the naked eye.