I like snap to edge, but I like margins (1 px left and right, gives me enough room to get to desktop menu and window list).
Margins work fine for maximizing windows. Unfortunately, they aren't honored for snap to "edge." (I don't think they're honored for initial placement either.)
Consequently, when I move a window near the edge, it snaps to the edge, ignoring the maring, and prevents me from getting to the desktop menus -- defeating the purpose for which I use margins in the first place.
Desired behavior: snapping is to the margin rather than to the actual edge.