I don't think anyone mentioned not having lower FPS in WZ. But there is a huge difference between dropping from let's say 80FPS to 10FPS and dropping from 110FPS to 40FPS. Sure, you'll notice the drop in both situations, but one remains playable, while the other does not. And it's a sharp contrast to PVE, where I never have FPS drops like that, runs smooth as butter (or, as I mentioned, games like 64-player BF3, which requires a LOT more player interaction, but runs fine on my PC).
For me it's not unplayable, but enough to be annoyed by it. Anyway, my core i5 and memory should be delivered to my doorstep in about 5 hours, so I'll install them right away and post here about the results.