Draconic Bloodline subclass as Sorcerer gives you at lvl 6 a big bonus to your spell damage by adding your Charisma modifier.
However this damage is only applied to the damage type according to your chosen Draconic Bloodline (fire, acid, lightning, cold or poison).
The problem is that in the currently available Sorcerer spells the damage types are extremely uneven.
For example (not counting cantrips and Chromatic Orb) the Fire type has 4 spells while Poison has 2 and Acid has ZERO...
To make it worse the Fire type also has the best spell for this purpose (Scorching Ray) because it will receive the full Charisma modifier to damage for EACH Ray it fires.
Please consider rebalancing this part of the Sorcerer class so that the choice between Dragon Bloodline types is more viable & interesting.