Ridley's Cohort said:
No, not really. Empower is very efficient in a way that Quicken is not, because Quicken chews through high level spell slots and low level spell slots at the same time.
If you want to maximize damage during a single round or two of combat, go with Quicken.
If you want to maximaize damage over the course of several rounds, go with Empower.
Perhaps, but it also depends on how many battles you can expect to be in before resting and regaining spells. In my experience, the wizard is the first one in the group to suggest that the party might be overextending itself (Uh, guys....I'm outta fireballs). I'm not convinced that the advantage you gain for casting an empowered fireball and keeping the third slot offsets the power of casting two fireballs (one quickened, one normal).