What did the client care about more, privacy or looks? Up there, an 8-foot vinyl is basically a solid wall, which is great if they have close neighbors. But cedar needs a lot more upkeep with that rain, even if it looks nicer at first. I'd probably lean vinyl for the low maintenance, unless they really wanted that natural wood look.
Honestly, it's a fence. How much deep thought does a plank of wood or plastic really need? People act like picking cedar over vinyl is a life choice. It'll get rained on and maybe fade, same as everything else outside. Just pick one and move on with your day.