As for poise in Dark Souls 2. It is very important. However, it is the other side of the table compared to Dark Souls 1. Poise isn't that important on armors, but poise damage is very important on weapons. Particularly later in the game when PvE enemies have absolutely ridiculous amounts of poise.
In other news. Just beat the Dancer with a soul level 1 deprived with a plus 3 weapon. Almost got her on the first try. Then didn't come close for the next 5 lol. Took me 15+ attempts.