The effect of a view's "iOS 6/7 Deltas" depends on the 'View as` settings as specified in the 'Interface Builder Document' inspector (select 'View' -> 'Utilities' -> 'Show Utilities', then click on the left-most icon on top of the utilities-pane and look at the responsible 'Interface Builder Document' section's 'View as' PopUpList).
Tweak your "iOS 6/7 Deltas" to adjust for the iOS version that is currently not showing (e.g. if you have set 'View as' to 'iOS7 and later', tweak the deltas for 'iOS 6.1 and Earlier').
Hence, your deltaY settings of "-20" are correct only, if you have set 'View as' to 'iOS 7.0 and Later'. Once your setting are correct, you can play with the 'View as' PopUpList and your VC will always look correct right away.
Hope, this helps.