My guess is that if you get too near the edge, and don't calm things down together, this could hold true for karezza as well. I wish researchers were investigating all the options better.
In karezza, the sex doesn't end in orgasm. But that doesn't mean it's anti-climactic.
“So she thoroughly taught him that one cannot take pleasure without giving pleasure, and that every gesture, every caress, every touch, every glance, every last bit of the body has its secret, which brings happiness to the person who knows how to wake it. She taught him that after a celebration of love the lovers should not part without admiring each other, without being conquered or having conquered, so that neither is bleak or glutted or has the bad feeling of being used or misused.”
Men are reporting that Viagra works with porn, and with partners not at all.
German medical doctor and neurologist speaks about porn's effects on relationships.
German with English subtitles. Excellent.