Kwin_gles on nvidia 337.12

Question

Just wanted to share my experience trying out kwin_gles on nvidia 337.12.  So far it is working well with no crashes.  The blur effect was causing artifacts, but after turning it off I haven't had any other problems.
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce GTX 660/PCIe/SSE2
OpenGL version string: OpenGL ES 2.0 337.12
OpenGL shading language version string: OpenGL ES GLSL ES 1.00
Driver: NVIDIA
Driver version: 0.0
GPU class: Unknown
OpenGL version: 2.0
GLSL version: 1.0
X server version: 1.15.1
Linux kernel version: 3.14.1
Direct rendering: yes
Requires strict binding: no
GLSL shaders: yes
Texture NPOT support: yes
Virtual Machine: no
kwin(3793) KWin::EglOnXBackend::init: eglPostSubBufferNV not supported, have to enable buffer preservation - which breaks v-sync and performance
Despite the message on the last line, v-sync is working correctly at 110hz and I have not noticed any performance issues.  I am running four monitors with the following effects enabled:
Dashboard
Fade
Kscreen
Login
Logout
Maximize
Minimize Animation
Mouse Mark
Scale In
Screen Edge
Sliding popups
Taskbar Thumbnails
Translucency
Wobbly Windows
Dialog Parent
Dis Screen for Administrator Mode
Cover Switch
Desktop Cube Animation
Present Windows

Answer 1

Wondering if this is related to an issue I'm having with my laptop (also an old, actually really old nvidia card). If so, I think I've isolated it to some sort of power management bug - as long as I move the mouse (I think keyboard mashing works too) while it loads the GUI, it's fine, but otherwise I get a black screen. I haven't had time to troubleshoot it much yet, but thought I'd toss this here in case it helps narrow down your search.