I see you have planned a DG with uni 80. nice , nice.
In my guild backs in caps 85/90, my DG friends has done the the test with all the uni 80.
Based on their experience,
Life : PvE set that is useless for upper dungeon raid , good for Auto-hunt and Ariela farming, rendered naked in PvP.
Dawn : Sometimes good in PvE, but that depends on the proc chance, although Dawn has partial
'tankiness', as the caps will be increased, the tankiness will be predicted dwindling as compared
to new gear(and weapon) power in PvP.
Twilight : The proc guaranteed crit, still good for PvE, indeed can allow to solo Abyss Hard,
as long as you not stuck on the reflect from that Jerennis. Somehow, it is overhyped in PvP,
due to DG sneakiness mechanism. hm, Irony of Twi " Proc on stealth , Proc after spam-skill end"
Arma : Somehow it is better from Twi DG on +12. either in PvE or PvP. but as you has mentioned, Arma is
OP unless encounter tanks.
All the Uni80 tested has +8 and above gear.
Based on present gaming experience, i think you may found some what has been stated above is not valid anymore.