The 18-70 is a great lens for the price. Plenty sharp enough for most purposes ( up to A3 from a D200) but not the fastest glass available. Not a lot wrong with the 18-55 but not quite as sharp and they distort a bit more at the wide end.
If I hadn't upgraded to FF, I would have kept the 18-70 but since it's a Dx lens (and it was a sale clincher when the D200 went) I didn't need it any more.