Remarkably, even the NTSC games have issues. You can see that with the performance snapshot of R4 Ridge Racer Type 4 embedded below. Original hardware runs this title locked at 30fps with perfect frame-pacing - a new frame is delivered every two screen refreshes without fail. Running under emulation on the PlayStation Classic, not only are frames delivered with 'blips' adding some stutter, but there also appear to be performance dips too - which do not occur in the game running on original hardware. So even if Sony had delivered a full NTSC line-up, we'd still have problems with this product falling short of the quality delivered by the actual PlayStation.
Moving onto the PAL titles, the situation worsens. Tekken 3 does indeed run at 83.3 per cent of its intended speed, but more than that is the fact that a 50Hz gameplay is dropped into the Classic's 60Hz output, giving obvious judder. Looking at raw video captures, every sixth frame is a duplicate - there isn't even the rudimentary frame-blending used in PAL PS2 Classics running on PlayStation 4. In fact, Tekken 3 also includes regular 50ms frame-time spikes - two dropped frames in succession, something that shouldn't happen.
But it's the original 30Hz titles that fare worse. As they are based on PAL code, the maximum frame-rate here will be 25fps. Looking at Battle Arena Toshinden, that is indeed the case with the PlayStation Classic's output - but it's actually worse than that as in addition to the reduced frame-rate, you also see variations in frame delivery too. There's little consistency here, meaning that gameplay suffers from obvious stutter. It's a really, really poor showing here.