ok, so with the wrapper, but using 2d mode, using PGCC Beta near the river, FPS was somewhere around 150-170, hard to tell. the low dips were usually around 110 (and this just standing still, see what i mean with the odd frame rate spiking?).
with shiny water on, it still looked like FPS was in the 150+ (certainly 130+) region, with the low dips however now sometimes at 30 (you know, that recurring one really slow frame every odd second)
edit: with vsync forced on i see literally no difference with shiny water on or off. 120 average, 90 lower dip value from trace fps
i don't actually know what you are looking for. i personally never had issues with shiny water, like i read many had (crashing and such). As far as NWN performance goes, there certainly was a dip a few years ago, when driver support for special NWN features was dropped. At some time a few years ago there was a years long ongoing campaign in the Nvidia forums to readd some optimizations for NWN, because the visible cloaks were for some reason suddenly killing performance.
Since a few years now however, i feel that current GPUs are simply brute forcing the game, and running at well enough FPS despite complete lack of any driver optimizations. On my Intel Atom i run at 20 FPS+ with shadows disabled. That's the lowest end you can get today. Its a 6 Watt APU.