yeah, but all that depends on the RAW -vs- RAI of RoS.
Actually RAI is debatable which makes it worse.
Great feat either way of course.
***
Also, Snowcasting.
*ahem*
Snowcasting
Adds the [Cold] descriptor.
Cold Spell Specialization isn't Metamagic and that's +2 per die.
Cold Snap isn't Metamagic and that's +1 per die.
Come to think of it, an Archmage's Mastery of Elements isn't Metamagic either. Apply Snowcast for valid target and go [Fire] for...
Caustic Mire & Raging Flame for another +2 per die.
Greater Arcane Fusion is
one spell. So even if three instances of Magic Missile was the result, I still only cast one spell.
1d4+9 per missile (savant don't apply), 8 missiles per spell (ros+1/prc+2), 276 damage (92 per).