yes, 3x3 pcf/soft shadow. (blurring) But, still seeing 'chain-saw' edges, especially in distant cascades .... What type of filtering can improve the situation? maybe, EVSM?
Variance shadow mapping (Of one implementation or another) can indeed get a lot softer (without noise) compared to PCF. I'm pretty sure Crytek uses VSM on their most distant cascades both to hackily simulate large penumbras as well as avoid any glaring aliasing.
Still, blurring is only going to get you so much. The first time I saw temporal aliasing was for shadows anyway, so you might want to try that. Crytek (again) had a reprojection technique to avoid ghosting for temporal aliasing. It was for scene aliasing rather than shadow aliasing, but the same principles should apply. You can find it somewhere under Crytek's presentations page. http://www.crytek.com/cryengine/presentations