One of the things that bothers me about VR/AR headsets is the FOV as it (for me at least) is what truly disconnects me from a scene. The small FOV feels like I have a scuba-diving mask on. At least on this parameter Q3 is better than Q2 and while it's far from perfect it's still enough to bring me more immersion.
The color AR feature I find is obviously way superior to the greyscale of Q2. AR porn I think has the potential to be the next big thing but I still think it needs work to truly get there but there are moments when I get carry away to another place.... it's when you really get the model in the right place... it just 'hits harder' than any VR porn scene I've tried. Unfortunately there's still much work to get the model in the right place and with position change it feels like you have to start over.
I also play Demeo and Eleven VR and both have AR features and that's frankly awesome with AR in colors.
My biggest issue so far with the Q3 though is that it gets really uncomfortable after a while. It feels like it bores into my skull - particularly around the eyes. I can't loosen the grip as it then slides around. However it can of course be a issue that only I have but I never had this issue with the Q2. Hopefully I can solve it when more 3rd party products comes out.
I've seen others complain about battery life. I haven't really noticed much difference with the Q2 so far.
In regards to image fidelity I think games and menus are sharper and more crisp but in porn scenes I see no real different. That said I'm that kind of person that isn't as affected by imperfections here. I can't remember when I last noticed the SDE on either Q2 or Q3 for example. For me again the FOV is a much more pressing issue where again Q3 is a step in the right direction.