The biggest problem I have with the Windlight client is that about 10% of the avatars do not rez at all. I just see nametags floating in space. In a previous version from last week, some times it would de-rez entire wall sections of buildings I’m inside, but that dosen’t seem to be a problem anymore.
The best part of Windlight isn’t the cool water and realistic clouds (I barely notice that anyway), but the fact that it runs smoother. Though I don’t think it’s due to it being a better renderer, I think it’s due to the fact that it the client automatically adjusts graphical settings based on your PC’s performance, better than the standard viewer. Plus all of those graphical performance tweaks have been simplified now, and consolidated on the same page in preferences.
As soon as they fix the invisible avatar problem; Windlight ought to be the standard client for all.