Upload & Sell: Off
I had the 16-85 mm f/3.5-5.6 VR (sold in favour of eating one month), and it is indeed an attractive lens. To my mind, there isnít a perfect FX equivalent.
The 24-120 mm f/4 VR that you mention is perhaps your best bet, but itís much larger, more ambitious, and more expensive. At the long end itís twice as bright as the 16-85, plus it covers the FX frame which is over twice as big as DX. So it supplies over four times more light to the sensor, and to do that it has to be bigger. Much bigger. The 16-85 is 72 ◊ 85 mm and 485 g, while the 24-120 is 84 ◊ 103.5 mm and 710 g.
For this reason, you might also consider the new 24-85 mm f/3.5-4.5 VR. Itís a lower zoom range, but in size (78 ◊ 82 mm, 465 g) and price itís a closer equivalent to the 16-85.