I see the passive being very handy, and i've been recently testing all sorts of different specs
the issue is lack of instants. melee chasing you = no casts. none, no hard casts. this is where warden shines, because you can heal so much on the run.
i can see the huge healbombs being handy but in return you get no: ridiculous amount of hots (and therefore shield greaters procs, i have both), ser procs (pretty sure HShowers is currently bugged, but i'm not going to elaborate because i dont want it nerfed), as well as the reflect, cleanse hot, double silence
so while i can see deep sent being quite nice for some fights, in recent times i've been ... 'favored' with '1' a lot more frequently. I just don't find deep sent to be all that survivable. If the other team doesn't know my name, yes it's great. otherwise... idk