First impressions is the user manager in 3.4 feels much smoother.
I haven't loaded it up with a lot of users yet.
It feels so much smoother that I went to check on my least fave part of Zentyal s4stnc
I thought it might of gone, but nope still there.
Definitely feels smoother and much more responsive.
PS I have HA disabled but still some stuff going on in the background