If you have NVIDIA GPU, overbright works with OpenGL renderer if you enable extension limit with NVIDIA Profile Inspector for hl.exe, though it also disables multi-texturing (no idea what that does visually). With D3D, vision under water is crystal clear (which is wrong), no fogging in the distance. Judging by one of my old posts on this forum, some textures may also have an issue with color banding, though can't recall where it's apparent. "Loading" sprite also looks weird to me under D3D, at least without forcing alternate pixel center. Forcing MSAA in general shouldn't be an issue with OpenGL.
They claim overbrights are fixed with Anniversary Update, though it doesn't seem to work on my end (NVIDIA GeForce GTX 750 Ti, driver version 546.29 from late 2023). Regardless, I think it's the most polished version overall. You can add back 3D sound and EAX with combination of MetaHook + MetaAudio plugin. MetaAudio does fix one issue with original sound renderer with cutting off sound playback of certain entities, eg. I notice in Hazard Course, if you get away from the talking hologram and come back, its sound is permanently cut while it keeps playing with MetaAudio.
Years ago, I tried patching some annoyances of WON version here, though menus are still horrible (can at least force native resolution with command line parameters to not suffer from resolution switches), there's none of bugfixes in server and client logic, no HUD scaling and other fixes from Anniversary Update etc., though if you lookup the original Xash3D engine on ModDB, from its extras, you can take valve/dlls/hl.dll and valve/cl_dlls/client.dll and copy them your WON installation to get some smaller bug fixes in server and client logic.
Still, Half-Life being Half-Life, there are always some glitches, so the question is, which version do you find the least distressing? 😜