As the prof pointed out, the basic advantage is that, in exchange for your move action, you can gain a +1 caster level bonus.
Which, to a lot of folk at the time, didn't seem like much, but ... it's an extra d6 on a Fireball, extended range, extended durations, possibly increased number of targets. It's a subtle but powerful boost. And thats without training yourself on how to use that extra juice. The
Raze feat chain ends up with some fairly significant advantages.