To touch a little more deeply on Dragon for a second...
It almost assuredly has less time in design and development for tweaks and changes, so it might be considered less safe than books in that sense.
It almost assuredly has less moving pieces, so is easier to balance in that sense - for example, AV had so much going on and is so densely packed that it was almost guaranteed to let loose a few gamebreakers.
Dragon material is given heavy feedback by readers on the WotC forums and they incorporate that feedback as errata into the final version published at the end of the month - this is a much faster and more rigorous feedback loop than is given for any of the published books which only make changes in truly egregious cases.
Dragon material published at the end of the month doesn't really have a ton of time for updates, so profits least from that arrangement.
Books get full and official errata channels so the truly bad stuff does get fixed eventually. At least in theory. *warily eyes a number of save penalty items and, say, Careful Attack*
So, there are some stinkers - yeah, Cannith Goggles are clearly just wrong - but I'd contend that a very healthy slice of every rules dense book so far has some clearly wrong stuff (Consecrated Ground, Guileful Switch, Spitting Cobra Stance, etc)