I'm using a cia on a N3DS with DSP audio, disabled audio sync, disabled video sync, and FFT still runs so excruciatingly slow it's not at all enjoyable.
On the other hand Civ 2 runs perfectly without any adjustments at all. (The menu system ruins that game, but that's hardly the emulator's fault!)
For the most part my experience is that the large majority of PSX games are more like the former than the latter. The emulator still has quite a ways to go to be more than a neat demonstration of potential.