Information about super-happy sims is a little vague, so I looked up some details in the game files. At 50 mood, a sim is in the "super" part of the mood bar (the visually squeezed point), and gets 0.3 lifetime happiness per sim-minute. Each +1 point of mood above 50 adds:
+1% skill rate
+0.007 lifetime happiness per minute
150 mood is the maximum mood in the default game, at the top of the mood bar, and cannot go higher. At 150 mood sims get 1 lifetime happiness per minute, +100% skill rate, and +100% work promotion rate.
The super part of the bar does not appear to correlate to any mood status. "Very happy" starts at 25 mood, and "Elated" starts at 75 mood, while the super threshold is 50 mood.
