Guild Wars 2

Toughness is better if you use alot of heal/life-siphon
Only if you do NOT utilize any of that, Vitality is better.

Temple sets in general are bad, because they offer no pure specific stats, only mixtures of sets. Get another Set of Armor and transmogrify if the skin is important.
http://wiki.guildwars2.com/wiki/Item_nomenclature
Read up here what you need.

You can mix from different temples and piece together a matching set with some stats, or get 4-5 pieces of the same stat. There are only a few stat choices (3, think) between the temples. You will have a lot more stat options with crafted or dungeon sets.

There isn’t a best stat for necro (or any profession), what it really depends on is the build you are using. You said you wanted AoE/damage, so some focus on power/precision will be needed, and the Temple sets don’t offer much there outside of mixing power/toughess/vitality and condition/precision/toughness sets.

http://dulfy.net/2012/10/03/gw2-endgame-gearing-guide/
http://dulfy.net/2012/09/08/gw2-templegod-karma-armor-sets/

Temple armor is not that bad. I bought a Grenth set. The runes are not so good but the set includes 3 rabid and 3 soldier’s with emphasis on toughness. You can mix and match armor from any temple but you will need to run a few dungeons if you want a whole soldier’s set. Soldier’s legs are not available for temple light armor. Still, balance is actually not bad and toughness seems to pay off better than vitality because Necromancers do not heal as well as a couple other professions so a larger health pool might be a waste after the first couple of hits.

If you are really new to L80 exotic armor, you might wish to stay with one rune set rather than mixing armor and having to crunch over some new runes but, then again, Rune of the Undead is pretty cheap and very decent. The only reason not to go with rune of the undead is to pick up specific bonuses like increased condition duration.

Obviously Grenth, hello patron god of Necros~

I mixed up Lyssa and Grenth to get as most precision toughness and condition damage as I could. Since there is no light chest piece with those stats I just went “screw it” and got the power/toughness/vit set. Sacrificed one ring for full precision cond damage.

Temple armor is good but I just HATE how kittening generic it looks. It’s L80 Exotic max armor and it looks like it’s some l40 crafted piece of junk!!!

For runes, I ground up some TA tokens and got Runes of the Nightmare, good stuff.