I'll respond to this and [MENTION=6696971]Manbearcat[/MENTION] here. I don't really disagree with most of the rest of he said. I'll second his observation that some of DWs mechanics can really add to cognitive overload during play (especially on the DMs side)
I think that [MENTION=6696971]Manbearcat[/MENTION] was saying that D&D adds to cognitive overload (and thereby implying that DW doesn't, or at least not to the same extent).
I think that some of the skill stuff was written in a much looser style. (I.e. interactions with the action economy are largely unspecified) I don't feel that 5e and DW are the same fame in very much else at all, mechanically. I do feel like maybe the wotc team took some baby steps in that direction (intentionally or not) as part of the whole "rulings not rules" mantra.
On this point, to be honest I'm not seeing much difference from the non-combat side of 4e, which is likewise light on action economy (I've always read "everyone takes turns in a skill challenge" as an instruction to the GM for framing fiction that challenges all PCs, not as a metagame stipulation of action economy).
I'll agree that it resembles DW (and BW, etc) but in 4e, as in 5e, you get the finicky stuff around multi-dimensionality, not inadvertantly short-changing or overrewarding certain builds that exploit that multi-dimensionality etc. That said, Stealth has not caused me any practical problems in 4e that I can recall (other than having to remember where my invisible and hidden token is when I take it off the map!).
Depending on who you ask, you're either right or wrong. In fact, I presumed much the same thing, except (as has been pointed out to me). Defy Danger with Dex is about moving quickly or acrobatically to avoid harm*. Generally, most applications of stealth in play don't involve that.
There's blogs and articles about why Defy Danger is absolutely wrong for adjudicating stealth and it should all be handled through fictional positioning and GM moves. (A discussion notably absent in the DW rules, IMO.)
Then again Defy Danger with Dex is what everyone presumes is the correct response, dropping or ignoring what is perfectly clear to those writing the articles and blogs.
To be honest my DW experience is limited - I haven't GMed, and my play was under [MENTION=6696971]Manbearcat[/MENTION]'s aeigs as GM so it may not be a surprise that he and I share the Defy Danger intuition.
Personally I don't see why this coudn't be handled on a table-by-table basis. Is it going to break the game to go one way or another (I don't see it)? And it's not as if there's DW organised play that demands uniformity, is there?
Purely for the sake of advancing human knowledge rather than pushing a point, I extracted these quotes from the rulebook:
p 18
A character can’t take the fictional action that triggers a move without that move occurring. For example, if Isaac tells the GM that his character dashes past a crazed axe-wielding orc to the open door, he makes the defy danger move because its trigger is “when you act despite an imminent threat.” Isaac can’t just describe his character running past the orc without making the defy danger move and he can’t make the defy danger move without acting despite an imminent threat or suffering a calamity. The moves and the fiction go hand-in-hand.
p50
The defy danger option for Dexterity looks like something I might be doing to dive out of the way of a spell
p 62
You defy danger when you do something in the face of impending peril. This may seem like a catch-all. It is! Defy danger is for those times when it seems like you clearly should be rolling but no other move applies.
[DEX is invoked] by getting out of the way or acting fast
p 169
The thief disables traps, sneaks, and picks locks.
In the thief class, I didn't immediately notice anything very sneaky other than high DEX, which suggests that DEX should somehow feed into sneaking. Otherwise I agree the DEX defy danger test tends to emphasis acrobatics/speed rathter than Stealth.
On the flip side, while I don't know the GM moves very well, it wasn't clear to me what move would be used to frame stealth by way of fictional positioning.
If the "imminent threat" that triggers Defy Danger
is the threat of being noticed/caught, then I think a good DW GM should allow for multiple approaches - DEX for stealth, STR to distract the potential spotters by pushing a boulder down from the top of the hill, CHA to nonchalantly/authoritatively stroll past them (analogous to BW's Inconspicuous skil, which I think is something I've missed in other systems eg RM and to a lesser extent 4e), etc.