It's a mixed bag. Most games work well, which is great, but the virtual immersion mode... not so much, which compromises this port's obvious main point. I'm trying A LOT of games -around 50 so far at the moment- and only a very small percentage of them displayed a true stereoscopic 3D depth effect - Indiana Jones and the Staff of Kings, OutRun 2, Call of Duty -graphically broken to unplayable levels with 3D turned on, however, but did output true 3D regardless-, Soul Calibur, Ace Combat -not sure which ATM, but it's the one that includes the cockpit view not available on the other- and Wipeout -again, not sure which one, but as both share the same engine it's a fair bet it applies to both-. Based on this empirical experience and according to this fairly sizeable sample, I'd say at the moment only a meager 10% of PPSSPP games, which unfortunately does NOT include Gran Turismo -the one I was most excited about- offer a true 3D effect with the corresponding settings turned on, whilst the rest of them simply present the action as a plain 2D feed spread over a 360º spherical projection, thus outputing the same exact image to both eyes with no sense of depth at all except maybe for the UI and menus in some cases. This may contribute in creating a placebo effect that undoubtedly makes certain people with dodgy depth perception to actually feel as if the game was presented to them in 3D, although really it isn't so.
I'm keeping the emu installed and will be watching and hoping for further progress and advances in the discussed area -as other technical aspects are sound and the app performs quite well otherwise- but for those with long VR teeth who know their stuff and happen to stumble with this comment whilst deciding wether to give this port a try, be aware and keep your expectations in check. If the lack of 3D depth puts you off and you're hoping to enjoy your favorite PSP game in virtual reality on your Quest, the odds are against you. Roughly 10 to 1, according to math.
P.S. As I mentioned, OutRun outputs 3D. However, the scale of every element feels way off, like watching a toy diorama -the distance between the two in-game virtual cameras creating the 3D effect is too wide-. This highlights the need for an option to tweak that aspect on the settings menu. Regardless of the lack of 3D depth on most games, adressing that issue would be a step in the right direction, IMHO. Thank you for your hard work and dedication just the same. It's honestly appreciated in spite of my nitpicking.