As an owner of two white iPhones, I can safely say that they are affected by scuff-gate, but not to the same extreme.
The white iPhone's rear casing does not scratch very easily, nor do the sides. However, I have had 2 separate scratches, which showed a slightly darker shade of silver. Using a chrome polish, it was possible to remove them completely.
One big issue is the chamfered edge. It is very delicate and extremely easy to chip/scratch.
Overall, the white model is better for long-term condition