Changes I've found:
Targeting is now to imaginary cylinders rather than actual model.
Nothing targets multiple cubes any more (bye bye crazy Plague mortar one shotting half the opposing strike team)
Doubling/tripling the opponent's roll for stuff like extra free actions is no longer a thing (bye bye melee monsters doing crazy chain moves across the battlefield eating multiple opponents).
All seems good to me as the above two seemed to be what killed the fun for people playing against me previously.