Beetle HW runs now? (Afair it got a dynarec update recently, right?)
Usually Beetle HW didnt run on anything other than high spec PCs. And upscaling beyond native PSX resolution was beyond the scope of lower powered devices certainly. It is accurate though, and it has perspective consistent texture dewarping, which makes PSX games look like an entirely different generation in many 3D games. (They always 'wobbled into place' on real hardware as well beetle can fix this.)
Normally the reason to go with PCSX Rearmed, is because of speed, and the ability to set render resolution to 2x or 3x. But the retroarch core so far isnt GPU accelerated, and can only do 1x so far (Thats with 1.5Ghz overclock). As a tradeoff PCSX Rearmed is far less accurate (soundglitches, flimmering textures) - but not to a point where people wouldnt still enjoy the games they are playing. (PS Classic is a hell of an emulation plattform once modded, and it only does PCSX Rearmed.
)
Running PSX games at 2x or 3x render resolution, also improves them very much visually - so for many people this alone will be the deciding factor. (But sadly - not on the Switch so far.
(1x only))
I've played FF8 Pal at NTSC Speeds without borders and 2x resolution on the PS Classic (PSCX Rearmed), past disc one at least, and loved it. Sound stutters and wrong swirl animations, when entering battles included.
--
I've played Chrono Cross on the Switch extensively (even using some filter afair), and had little to no problems (set to 16:10 for that game specifically (as the art work copes quite well)).
I remember that with Chrono Trigger (PSX), I got frequent random crashing.
But I've played and finished the SNES version on the Switch (cpajustes SNES emu
- but you can use snes9x in retroarch as well) a while back. Play that one. Its more charming without the FMVs. Imho.