Well, Jab is a much more reliant source of Chi. I've spent way too many times casting Soothing, trying to proc a third Chi for a fast Enveloping with no success...
Also, if the damage is not that severe you can just auto-attack and still get some reasonable healing out of it. For me, fistweaving is more mana efficient and not so RNG. Best bet is to give both a try and see how you do or witch you like more.