At my outit there is no regulation considering the landing flap setting - Flaps 3 and Full are both regular landing flap settings.
Generally, most of our pilots use flaps Full as landing flap setting.
Me - I prefer flaps Full on most landings, but use 3 in gusty/strong wind conditions and always when flying the A321 - regardless of the wind conditions, as I think it gives me a much better control compared to a flaps full landing.
The argument of tailstrike protection on the A321 is neglectable I think, as tests have proven that while the pitch difference between flaps 3 & flaps Full on the A319/320 is about 2.5° (~2.5° with flaps Full and ~5° with flaps 3), it is just marginal on the A321 (~2.5° compared to ~2.7°).