Welcome @Nonamelix

Hopefully Fae or Jonas will respond with an authoritative answer, but my understanding is that the EAP245V3 and EAP265V1 are identical from a hardware perspectve and that only software optimizations were changes to support more (e.g. >100) STA's.  Generally speaking the 265's seem to be for a very niche business application.

I've used the 225V3's and 245V3's and both work very well.  I recently upgraded to the 245's and they are ~20% faster under load (~45 STA's) despite the fact that all of my clients are 1x1 and 2x2.

-Jonathan