Remaining items are:
- Multitexturing the sky warp (UPDATE - done).
- Tweaking particle size to match GLQuake (UPDATE - done).
- Adding in the remaining vid_* commands.
- Fixing up the loading disc (UPDATE - deferred).
- Removing some legacy mess from vidnt (UPDATE - deferred).
- r_shadows 1 mode (UPDATE - done).
- Water and sky textures on brush models.
- Changing the viewport to match scr_viewsize values (UPDATE - done).
Aside from that it's very playable as it is. If you're not too bothered about any of the above, you could have a solid game of traditional ID1 on it and not notice anything too different. For reference, on an Intel 910/915 D3DProQuake gets about 56 FPS, this one gets near 90 (it was over 120 until Windows Update decided it wanted to be my friend), and with ample headroom for optimization.