here is an interesting talk from thanissaro bhikkhu in which he talks about rapture (he says wellbeing is an equally accurate term) as one of the 7 factors of enlightenment.
http://www.dhammatalks.org/Archive/seven_factors/04%20Rapture%20(110822).mp3
i took two things away from this, one - an interesting method he often talks about to simply create well being and "lubricate" the process (i guess he'd fit right in with the pragmatic dharma crowd!) by suffusing the "breath energy" into all the parts of the body
the other - he talked about how some people experience rapture very intensely, but this isn't due to more concentration, but due to being starved of that sort of pleasure. this got me thinking a bit about how my practice has been very up and down. i tend to have some really good days, where i have constant intense felicity, then as time goes on i get used to it (am no longer starved and it becomes more refined) and get frustrated thinking i've somehow forgotten the practice or am doing something wrong, in so doing i make it much worse, starve myself of felicity again, start afresh and feel the intense felicity for another day or two.
i've heard other people talk about somewhat similar issues, maybe this would help to understand
side note, i suggest listening to some of his talks, he seems to be teaching buddhism of the variety that arrives actual freedom.
