I've just tried the new builds with support for the Oculus SDK 0.4.1 on the DK2 on the quake level renderer. There's several observations that I'd like to note down.

Latency

In both Chrome and Firefox the latency is still pretty high. It's perhaps a little bit higher in Chrome than firefox, but I could be wrong. I haven't measured it (how do I do that with the DK2?), but it looks to me to be around 100 - 120ms.

FPS

Both browsers don't reach 75fps (a requirement for the dk2) I think. Again it's hard to tell, but it doesn't look like it.

stuttering

Both browsers exhibit some stuttering. I don't know what that's connected to, but it looks like 2-3 dropped frames every now and then. It's visible for both walking around and moving the head. It could be GC stutters, it seems to be a bit more pronounced in chrome than in firefox (afaik firefox is more ahead with their incremental GC), but it could be related to other things (uploads, frame synchronization issues, what have you).

Popup dialogs

When Firefox goes into fullscreen and you haven't done that one the page before, it shows a dialog on top of the page to allow this. This dialog cannot be properly seen in Firefox. I don't know if Chrome does the same thing (their notification dialog is placed differently). On any account, popups like that should either not be done, or be VR compatible obviously.

Direct Mode

Neither browser supports direct mode so far.