Depends on the deployment. I find myself running a lot. I also found that outflanking with a Tervigon is rather nice, he may not spawn or be able to use half it's powers the turn it comes in, but the following turn it puts a lot of preasure on your opponent. If you deep strike a Trygon or two with it that's a lot of added pressure from that flank.
Due to how long nids get across the table I have found deep striking may be a solution to that problem. If you running a swarmlord and paid the 25 points on the tyrant you can easily get units in on turn 2 even with negative modifiers. Hince why I wish for drop pod models. The doom and trigon works great doing this, not a fan of the mawlock. I want to deep strike my gaunts, maybe devil gaunts in as well. The turn 2 deep strike assault would disrupt the enemy and allow you to be on the aggresive much sooner.
I am thinking of using spore mines more since it also disrupts the players deployment. Armies like Tau can take decent losses almost before turn one's shooting phase.
The problem with deep striking some armies have a lot of fire power. Which mean they can possibly win if they go first and be able to wipe the nid player off the board.
That being said I use the deathleaper and it always does well. What are you going to shoot at the doom, trigon, or the deathleaper first.