Is this a well known fact? Can I get a link to the study?
Well, to be fair I'm not able to point out any "Harvard Studies on Terraria DPS" and it seems no one online has bothered to do any DPS calculation online so yeah, fair point.
I'm only going off of this, the max a Stardust Dragon's DPS for example would be :
8,177 DPS (with armor/accessories)
Which by itself is an extremely good amount, now, pair that with OTHER weapons
at the same time and you easily have over 10k DPS.
Yeah true, there's no official "studies" but just looking at it, including the fact that they had to
nerf Stardust Dragon by 33% in 1.3.0.6 means that yeah it probably was a pretty powerful class, and hey, still probably is. But that's all speculation :3
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When it comes to the squishy-ness of the class:
Nebula: 46 Defense + Usual Buffs it gets for adding Health Regen...
Vortex: 62 Defense + Reduced Enemy Visibility
Solar: 78 Defense + 30% Damage Mitigation buff from set bonus.
Stardust: 38 Defense + Aggro Guardian (very useful :3 )
And of course a disability to protect yourself as you please Stardust Guardian's aggro doesn't work, I'd say that makes the Summoner class the squishy-est, but lemme know why you'd think otherwise.
EDIT:
Stardust Armor needs a big upgrade, being the worst out of the four end-game armors. Increasing the defense to 45 - 50, increasing the damage of the guardian to something like 100 and making the guardian's blast radius larger would be a bigger and fair upgrade to the armor. I know this addition would make a lot of people happy and excited.
And talking about the original post, I'd agree increasing the armor on the Stardust Armor to some minor extent, but the guardian isn't meant to be dealing damage, it's meant to make it so individual monsters
don't even have the chance to touch you by drawing enemies towards the guardian (aggro). It is certainly NOT the worst of the end-game armors, with no other class is it possible to stand still doing absolutely nothing and full clear Frost Moon/Martian/Pumpkin (yeah probably not Pumpkin).
But that's just a theory, a BALANCE THEORY