From the video above, its pretty clear the G2 is better at everything than the Q2 with the Index only having the edge in vertical FOV, horizontal FOV and refresh rate.
The Index beats the Q2 in most use-cases (but the margins are very small) apart from SDE, and trades blows in some games re: sharpness (I think the Q2 looks a bit better in Assetto but worse in others, sadly the poor colours don't help).
SDE: G2 > Q2 > Index
Sharpness: G2 > Index >/= Q2 (I thought Index looked better in most use cases except Assetto Corsa)
Compression: G2=Index >>> Q2 (very obvious in the snellen test)
Black levels G2 > Index >>>Q2 (as evidenced by the DCS test, the sky on the Q2 is very very grey and lets remember neither the G2 or Index have perfect blacks to begin with
Colours: G2 > Index >>>Q2
Vertical FOV: Index>>>G2 >Q2
Horizontal FOV: Index >>G2 >Q2
Refresh rate and motion: Index >>> G2 >>>>>>Q2 (until we get the 90hz update which has been confirmed to sacrifice further graphical fidelity)
So overall, I'd say its some interesting findings which were all in line with what I personally predicted. I don't want to toot my own horn too much. I've owned the Rift S, Quest, Index so it was fairly easy for me to speculate and come to clear conclusions unlike the fanboys who have set up camp in each different hardware developers dungeon.
Whats sad is this that is over the link cable, so the PCVR wireless virtual desktop solutions are likely EVEN worse. Still for the money, its good to see the Q2 is holding its own against far more expensive headsets, albiet the fact its obviously wasting some of its panel by not being able to fully take advantage of it. More dissapointing for the Q2 is Oculus continuously using poor contrast, poor black level LCD panels whilst Valve and HP are using far more superior options.
On the G2 front, it looks like an upgrade in nearly everything. Its clarity now has to become a benchmark for what we need in VR from the PC side of things.
The Q2 is also a benchmark for what we expect in portable VR, alas with no real competition.
Overall, I give the win clearly to the G2 but its amazing that nearly 18 months after the Index's release, it is still holding its own with the newer headsets. I guess in the VR market, it is kind of true that buy cheap, buy twice. Similarly the Q2 for the money is absolutely great, considering it gives visuals around a Valve Index, albiet with far worse colours, refresh rate, last generation controllers, compression artifacts BUT it does have the option of untethered portable VR for smaller games (sadly this comes with the poorer visuals). Its also still clearly the best adult VR entertainment device as it doesn't have a cable so you can take it to bed. *logs onto amazon and orders one*
My biggest take home message for myself is that HP have set a new standard not just for sharpness and clarity but for what we should come to expect from LCD panels on VR headsets. The colours simply look gorgeous. Valve need to take note, and obviously Oculus have a lot of homework to do if they want to match either the Index or G2 colours.
Whats very obvious is you are getting excellent value, no matter which headset you've gone with. If you bought an Index 18 months ago, you still have a top-tier VR headset which goes toe to toe and beats the competition in multiple parameters. If you buy a Q2, you're getting fantastic value on a versatile headset which can be portable and the G2 is the next evolution in VR visual fidelity with the best in class audio system in situ.