Solar Barrage is utterly useless atm. It gives you empower, but that empower only applies against one target. It also has a longer animation than Impulse and costs more.
I agree. Solar Barrage...I never ever ever see anyone using it, I tried it myself last year and it just has nothing to offer, AND the global cooldown after using it...
But it's less powerful and has less utility than sweeps and morphing to it causes you to miss out on on one of the hardest hitting range spells in the game, in dark flare.