So I hit 50 Sniper and tried this 16/2/23 build.
Result: I don't recommend it. It's extremely energy intensive. Read after the cut for the full analysis.
Here's the build:
You could even take out Adhesive Corrosives and go Lethal Purpose, and I don't think you'd see much difference in the energy usage.
The only thing that makes this build half-viable is that one point in Sniper's Nest.
Playstyle: Massive single-target burst. You're basically a cover-dependent Sniper (i.e. to take advantage of the in-cover energy bonus) with a few new tricks. You can't run around as this type of Lethality build. I used my regular "Marksmanship" sniper abilities on standard targets and saved DoT+Cull for Strong/Elite targets.
Pros: Very high damage in a short window.
Cons: Unsustainable energy usage. Cull uses 30 energy (~1/3 of your bar) and is on a nine-second cooldown. In order to make Cull hit well, you also have to have both of your poisons (Corrosive Dart and Corrosive Grenade) on your target. This is only worthwhile on strong or armored targets. You're still pretty much drained after one rotation.
Verdict: It's fun, but impractical. It also eats energy faster than about anything I've ever seen (including the old Engineering tree!). I could see some applications for this spec as a build in PvP, but even then I wouldn't recommend it because of the energy concerns. In PvP you want to be able to use your CC abilities and many of those cost energy. This build demands a large amount of energy and locks you down into one role: single-target burst DPS. You don't even have the option of "sustained" DPS anymore.
I'm of the opinion that the Lethality tree needs a little help right now, especially compared to the Marksmanship and Engineering trees. Although the Lethality playstyle can be fun it still comes with prohibitively high energy costs.
NB: It is impossible to get both Cull and EMP Discharge in the same build.
Questions, comments, or build testing requests? Leave them at the end of this post or email: Fentanyl213@gmail.com