Life vs Speed?

[God]

Personally I feel Life surge is better at least on NM's.

The evasion down will help more than a small haste since your helping jobs like Archer who stack multiple shots massively increasing dmg on BR WS's not to mention helps our own WS's from missing.

[Cantor]

Personally i use both if u open with life surge then hit it once so debuff sticks then u can switch to life and hit it and then have both debuffs active at once. on really long fights i will juggle them some if we dont have a 2nd lancer