Well, here's my feedback for these two versions:
Doomlord's version
The lightning balls travel fast, and that makes the spell more "lightning elemental". Homing and bouncing is just great, but it can be quite overpowered when you gather a lot of enemies around and cast the spell.
Aero's version
The balls grow bigger and bigger, which makes me feel it stronger and all. Upon casting, the balls can damage enemies who come in contact with them before they start to move to the target and during their pathways.
Overall, I'm impressed by the way these ball homing and bouncing, but I think the cast range should be fixed. So I voted for Doomlord. However, I prefer the combination of both versions.