I found some descriptions of jhana written by Brahm, which clears a few things up nicely.
If the happiness that arises with awareness of the breath is of the sensual excitement type, for example like waves of physical pleasure coursing through your body, then it will soon disappear when effort is relaxed, leaving one heavy and tired. It is of little use here. If the happiness is associated with the sense of achievement, for instance thinking “Wow! At last I’m getting somewhere in my meditation,” then it will often be followed by the achievement disintegrating, destroyed by the controller suddenly being aroused, ruined by the interfering ego. But ... happiness ... born of letting go, then one feels that one doesn’t need to say anything, or do anything. It becomes the happiness whose brother is freedom and whose sister is peace. It will grow all by itself in magnificent intensity, blossoming like a flower in the garden of Jhana.
3 different responses to jhana. Very interesting. I should have referred to him earlier, since he's one of the better teachers.
