Here is an update on my quake2 port. The port in general has seen a nice speed boost I think from a combination of fixes and changes picked up by the main project and my rework of the opengles code.
The video menu settings are unstable, so if you need a bigger res change gl_mode in the config file.
The gles port uses some techniques I used in glquake.
1. Convert vertex arrays into triangle strips and degen them if possible. Memory for the array grows as needed.
2. Convert textures to 16 bit format (rather than 32 bit)
3. Use driver mipmap (code enhancement)
might be other things but this is what come to mind right at this moment.