People post on this forum at a speed were you will not miss anything. Allow others to post freely; it makes the forums more active which is always postive.
Keep in mind when your checking other players profiles that they always run with a healer because they gear/spec for 3s and run dps/dps/healer.
This is my take on the 3 talents just so you have another opinion.
Supremacy: This is good if you want consistant damage over time. Also for Demo Locks it provides more HP via Sacrificial Pact. It is also one less button if you don't like cluttered bars or don't care to "think" about the tier for newer Locks.
Sacrifice: This is good if you want the control of all your damage in your hands and not half with a pet. Also good if you dislike pets or your pet dies allot or is targeted by teams/CC'd by teams. Also good for extra healing if running Drain life spec. Also good if running Charred Remains Destro spec for extra damage on Choas Bolts.
Service: This will basically allow your pet damage to be double the damage output for 25 seconds in the form of two pets. So it's a great cooldown to link with your other cooldowns when bursting. It also provides a instant stun, CC, or Silence like you said. It's also good if running Demonic Servitude for the double Doomguard.
That is a breakdown from more of a BG hero perspective but hope it helps.