Adarkar Wastes is a premium dual land for any Azorius (UW) deck, and one of the most underrated fixing options in the format. The reason it's so good: it enters untapped, always, with no conditions, no basic-type requirement, and no payment hoops. In a format defined by 100-card singleton consistency and the need to curve out reliably, untapped fixing is gold.
The 1 damage is a near-nonissue in Commander. Starting at 40 life with no clock pressure most games, pinging yourself for color is trivial — and you can always tap it for colorless when you don't need the color, avoiding the damage entirely.
It fits any UW deck: control, flicker/blink, tokens, stax, or as part of a Bant/Esper/Jeskai manabase. Pair it with the rest of the Coldsnap/Ice Age "painland" cycle.
When not to play it: aggressive low-life-total strategies (rare in EDH), or budget decks where you'd rather run cheaper taplands — but honestly, it's almost always worth it.