I think that taking 2 points in masochism are pretty good for levelling at the moment, i'm barely running into any major difficulties - only major one i've had is soloing arugal's shade in grizzly hills at 75 - being hit and having mana restored for PW:S and then nova'ing the crap outta the 10 odd mobs that spawn on him has helped immensly.
Not noticed a huge help from harnessed shadows - probably due to crit levels not being high enough to benefit from the talent. Primarily the majority of the time i dont factor in mind blast to my rotation as they die quicky enough without the 3 stacks. Its nice enough as a filler, but mind flay, SW
and my dots handle enough for me to worry about. There is very little downtime if any.