Just recently leveled my lock and started PVPing as demon. I know lots and lots of locks are debating on whether to use GoSupre or GofService (one for overall damage + sacPact buff, one for more burst) But how do you feel about Grimoire of Sacrifice? I have lately been using it and think it's working pretty well. The burst from the xtra 30% for your Chaos Wave is pretty significant (and I assume should do much more burst than Grim of Service).
And by picking this talent instead, I feel like using Felhunter is the better solution (and maybe even Dark Bargain>SacPact due to felpuppy's low health).
Just to be clear, I'm not saying that you should use Sac right off the start. But rather, macro it with demon soul and trinkets, just for that particular burst. And if the burst fails, we can instant summon the felpuppy back.
What is also good about this is that we now get 2 Silences. (Can macro the pet silence with the macro as well I think before it is sacrificed) and then gain our own command demon silence).
this is old news, the trade off was between GoSup and GoSac from the start, service was for those who wanted that extra control, the damage from service is nice and all but if u want burst you do the old GoSac with DA/trinket which yields better on demand burst than service by far , though it is tricky since you'd have to use demonic rebirth to resummon your pet after that , which makes you 1 pet summon short in case your pet is being killed ( which is becoming more frequent these days ), also using GoSac makes your sac pact weaker and not only that, you lose the 25% healing debuff from the wrathguard, felguard has 10% only, unless you want to run with a felhunter due to no other source of ranged interrupt on your team.
overall it's a trade off, if you can sacrifice some survivability , pet survivability ,a tad more sustained dmg and healing debuff for that extra on demand burst then it is the right choice for you , if you want a more well-rounded playstyle ,stick with GoSup.