I'd say that wings have two parts.
• Convenience of spam casting, which the boots do not give
• Ability to reach areas that others may not have reached to easily, which the boots do give.
It's not that the boots are OP. It's that Turbine has begun taking unique class aspects and giving them to everyone. They did it recently by allowing artificers to get DR breaking infusions like the Paladin Capstone and almost had the artificer ability to buff arcane spells at 20 minutes from scrolls. Each time Turbine does this, they take something away from the original class. In some cases, it's just the uniqueness of being able to fly around, in others, it's 35 damage per swing that a barbarian is now getting with a DR breaking eSoS.
It's starting to take away from the flavor of the game, imho, and could be a precedent leading to things like Evasion potions or Bard song clickies. If enough of these get out, playing one class won't be much different than playing another.