Stardust may be the best summoner armor, but the set bonus is pathetic.
The set bonus is not great, but the set in and off itself is superior in every way possible, when compared to other summoner sets.
And while Solar Armor's bonus is indeed versatile, I disagree strongly that it's the best. The damage reduction is better covered by Beetle Shell, the pseudothorns is handy but not that big a bonus in the grand scheme of things, and the dash always seems to take a backseat to attacking with my weapons (and I'm used to tapping to make small position adjustments, so it keeps activating when I don't want it to). I still find myself using Beetle Scale Mail because it provides more DPS and the other benefits of Solar are too minor for me to care.
Beetle shell may provide more percentage based reduction, but it provides a significantly lower boost to damage along with 5 less base armor. The extra 5% reduction per charge on the beetle shell are not much of a difference to begin with, which is especially true, after being hit once or twice. Also we have access to the worm scarf now, making that difference matter even less.
Shell provides 11% more melee dmg, 5% crit, and 6% more melee speed
Solar provides 22% more melee dmg, 17% crit and 15% more melee speed
When talking stats, we're talking permanently active stats here. They will always be there, no matter if you get hit or not. The peak of 15% more reduction on shell on the first hit taken is a joke in comparison. Let alone the fact that ANY amount of damage taken costs you a charge. Here Solar is at an advantage too, because it offers higher movespeed, making dodging easier in general and it also offers a quick sidestep-dodge that costs a charge but spares you the damage if performed successfully. If you rely on attack speed, beetle scale is still the proper choice, but some of the most powerful melee weapons do not even benefit from that speed boost that much, if at all, for example the Terrarian, paladin's hammer, or the solar eruption, also vampire knives have capped attack speed, same goes for the scourge of the corruptor.
The double tap-trigger is debateable though. I reckon some manner of seperate key, or a certain key combination like ctrl + double tap, or shift + double tap would have been fine as well.
Vortex and Stardust Armor are both objectively better than their predecessors. Having used Nebula, I can say that it's better than Spectre (does more damage than Spectre Mask, but steal heals). Is Solar Armor being a clear choice over Beetle Armor too much to ask for?
As I have stated, Solar armour is clearly superior to the beetle shell in more than one way. If you however favour a playstyle that requires a certain sets bonus to make it worthwhile, you've chosen to go all-in, as in ignoring other variants of playing.
As for doing more damage than the Nebula Blaze, both Nebula weapons are pretty bad. The projectile velocity on the Nebula Arcanum is way too slow, while the mana cost is crazy (40 mana, two full stars. With no boosts from equipment, that's 1/5 of your max mana). Meanwhile the Nebula Blaze is generally inferior to the Razorblade Typhoon, unless the Razorblade has no chance of hitting multiple targets (and even then, the Razorblade Typhoon consumes 1/3 the mana per second).
I agree on this one, even if we are lightyears off-topic now.
And using the Phantasm against Plantera is like using the Heat Ray against Destroyer. It's 2+ tiers after what you're testing it on, of course it's going to obliterate it. Consuming no mana is true of every ranged and melee weapon, and almost all ranged weapons can hit off-screen targets. Also, only nine weapons are not available before killing the Moon Lord.
Plantera is sporting 30.000 HP on a single target, -s i n g l e- being the keyword here. Killing that thing in less than 2.5 seconds means 13k-14k DPS on a single target and maybe even more on groups of enemies depending on the ammo. What more need you be told? The only weapon that can compare its DPS to these values is the last prism, which eats your mana in no time, forcing you to seize fire, recover via taking damage, or live with the mana sickness debuff, thus reducing DPS dramatically. Also the last prism is a moonlord exclusive drop, it is not craftable, mind you.