These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Evil Is Sexy: Foxfire and The Mink. Especially for Foxfire, who seduces Doctor Spectrum with a wink and a smile.
First Installment Wins: The 12-issues limited series was the first series with the Squadron Supreme as lead characters. But it was not the only one, "Death of a Universe" and "New World Order" were released a few years later, but not so acclaimed as the original.
Fridge Brilliance: The first uses of the Squadron Sinister / Squadron Supreme were just a "Take That" to DC. A "crossover" with DC characters, where the Marvel ones were always the better ones. The 1985 comic book took another angle: as they were "disposable" parodies, and not Marvel's most iconic characters, use them instead to write the type of stories that would never be written in either the DC or Marvel mainstream titles. At least by then. Anyone Can Die, "Firestorm" with radioactive powers gives cancer to others, superheroes bent on changing the world, on seeking a cure for cancer, giving up their secret identities on live television, "Green Arrow" messing with "Black Canary"'s mind to force her to love him (which is very close to rape), "Flash" with a machine-gun on a killing spree, "Superman" blind, and so on... But the most interesting one, "Batman" and "Superman" were not shown as best friends, but as rivals, with polar opposite views on the role of superheroes in the world. To the point that "Batman" actually made "kryptonite" bullet and seriously considered firing it to "Superman". The idea was so interesting that Frank Miller took it the following year for Batman: The Dark Knight Returns, and then it was used in the proper mainstream DC universe. But remember: the rivalry of Superman and Batman was invented by Marvel Comics.
Fridge Brilliance/Fridge Logic: The flaws in most of the Utopian technologies are pointed out during the series, the only one left out is the hibernaculam, but its flaws are pointed out indirectly earlier in the series when Tom Thumb goes to the future for a panacea cure only to find that people of the future have little need for medicine so they don't seem to have cures for the ailments of modern dying people.
Amphibian's real name, Kingsley Rice, has some Fridge Brilliance to it. At first, it just sounds like a clever, if slightly unusual, name. But compare him with Aquaman, whose real name is Arthur Curry. Kingsley and Arthur can obviously be used to make a comparison to King Arthur, whilst Curry and Rice are two dishes which go very well together. Aside from being based upon Aquaman, Amphibian was also named directly after him!
Older Than They Think: Some of the themes of Watchmen such as the morality of Knight Templar measures to ensure world peace were played with by Squadron Supreme before Watchmen.