At tier 4 you'll get the same defense debuff values regardless of which you choose, which makes the choice between more damage (Core) and getting ToHit Debuff (Radial). Since you can already get close to the to-hit floor using Darkest Night and Dark Servant, I would say the extra damage is the better path.
For incarnate trials in particular, you should be able to debuff the regular guys fine once you get your level shifts and the big guys will resist the debuffs anyway - so going for damage makes the most sense. YMMV, but that's my perspective.
Iscariot's Guide to the Tri-Form Warshade, version 2.1
I'm sorry that math > your paranoid delusions, but them's the breaks -- Nethergoat
P.E.R.C. Rep for Liberty server
Pretty sensible-sounding!
Persephone Ash, necro/dark practitioner, is doing iTrials now. I'm going with Musculature. With that power combo, do I have a reason to particularly favor the to-hit debuff help or the defense debuff help, while I'm doing lots of trials?