As opposed to what? Heart of the Praxic Fire for a super you never use? Gift of the Sun and Touch of Flame are the two best neutral perks the class possesses. Why not have them both?
That's really not different than me saying spamming grenades during radiance is by far your best ability, so wear praxic fire and pop your super every time there are orbs/ majors to get your super [b][i]right[/i][/b] back.
It wasn't HoPF the was nerfed directly. It was the delay between throwing a nade, and the next one beginning to charge. That's why you need gift of the sun.
HoPF still makes the recharge faster, on both nade and melee.
It sounds like you tested either without radiant will, or without maxed discipline. Maybe even without either.
Enemies move out of solar grenades. Touch of Flame and Viking Funeral will finish off a lot of enemies that would otherwise escape with a bit of health remaining. And like I said, the alternatives all suck.
I'm definitely not advocating the other perks. They damn sure suck. But not enough to give up gift of the sun, or praxic fire..
I'm not saying it's not useful, it's just a negligible amount of damage to sacrifice [i]anything[/i] for in PvE