I listened to both the 223 and 333 for a few minutes each on the AK100, my go to DAP for my FItEar customs.
The 223 are very much like a baby 435 quite similar in sonic presentation but not as detailed, resolving nor as accurate but more importantly, the 223 is so much more forgiving and for me will make a great daily beater...
The 333, detail wise is really in between the 223 and 435 but with the mids, especially the Vocals being fleshed out. I concur pretty much with what Cravenz says, although, I never found it too
forward and in your face as it still sounded coherent and together in it's presentation........
There is definitely a distinct and unique sound with the FitEar Private series, which is exceedingly additive