So, my takeaway after messing with V3.1 for a day and reading other anons.
For RP, v3.1 has natively shorter output. You can mostly fix this with prompting per >>106319389. Pic related is the result, >>106315981
shows output with no length guidance to v3.1. This is DS official API, and matches other's observations in the generals.
Going V3-0324 --> V3.1 is more of a tonal shift than V3-->V3-0324. V3-0324 fixed the earlier V3's annoying repetitiveness, but responded, tonally, the same. V3.1 is tonally different... and to me, looks like it's picked up a bit of the repetitiveness again. This is all pretty subjective though.
V3.1 may be an improvement in coding >>106319739. In which case, wish DS had released V3.1 as deepseek-code and left V3-0324 as deepseek-chat, since the latter IMHO is a preferable conversationalist. Echoing >>106319588 the personality of the -chat LLM shifted quite a bit.