I've found that two points in Kinetic Reservoir is almost a must, but additional points are wasted. The first point adds 2M/s, the second point adds an additional 3M/s. After that, additional points add only 1M/s extra. If you spam Kinetic Reservoir you will not run out of mana all the time and you won't need to guzzle stims. Plus, if you time it so that you are charging between fights and it runs out just as you attack you get a pretty huge damage boost for one or two attacks. Engineers can easily keep your life topped off, but their meager 1M/s buff from revive just isn't enough to keep your blue bar up.

I can't justify points in hammer when you have two other taunting abilities with bigger AoE.