Coming from StB, SMN feels a little weird. Then you realize that its rotation is composed of 2 disnjointed parts and it becomes really easy:

1) Aetherflow - Energy Drain/Siphon: this doesn't interact with trances anymore and instead it's just used for fester (single target) or painflare (3+ targets). Think of it as 3 sequential oGCD skills;
2) Trances (dreadwyrm, baha and phoenix): these are dictated by dreadwyrm trance's cd, which also determines how your dots are applied.