SMN in 3.0 had to upkeep DOTs 7-8 times per minute excluding Tri-Disaster, and followed a 60second rotation more forgiving on movement.
SMN in 4.0 need only upkeep a pair of DOTs once every two minutes, but follow a 120second rotation less forgiving on movement.

I personally think 4.0 is harder, but perhaps i'm still new to this gamestyle.