Created attachment 153543 [details] Example 1 Bisected it to this commit
Created attachment 153544 [details] Example 2
Created attachment 153545 [details] Example 1
Created attachment 153546 [details] Example 1
Created attachment 153547 [details] Example 2
*** This bug has been marked as a duplicate of bug 461358 ***
Created attachment 153979 [details] screencast showing the problem I've noticed the same thing - when windows are maximized, the new Breeze outline is gone and instead there 1 pixel of transparency that shows the wallpaper. If the wallpaper has some differentiation between pixels at the top line (very common for photographs), this becomes very jarring. Here's a screen cast showing how a window at Y=0 but not maximized has an outline which becomes transparent as you maximize it (the shake that happens is probably from the wobbly windows' maximize effect).
oops, just noticed the dup...