Advantages and disadvantages of ST-E2?

I have two Speedlites - a 430EX and a 580 EXII - and would now like a way to fire both off the camera. I'd be using the setup indoors pretty much all the time, for portrait work, and am considering the Canon ST-E2. Would this be a good solution, or should I be looking at something else?

Depends on what you want. If you want e-TTL options then it's worth looking into. I prefer to manually control speedlites as I can get consistent exposure from shot to shot. I think it's main disadvantage is the IR signal requires a direct line of sight to the speedlites. As such I would prefer radio triggers and some of the Chinese brands like the rf-602s are quite cheap yet reliable.

Indoors the signals can often bounce on walls and similar, and thus you can tuck a slave under the sofa and it will still work.
The ST-E2 does not allow manual control, not from the camera.