ST-E2 or 550EX?

I am using my 580EXII off camera right now with Pocket Wizard Plus II's, and I would like to be able to use ETTL and HSS. I was thinking of getting the ST-E2 transmitter, but I started thinking. Why wouldn't I just buy a 550EX flash to use as a master, instead of buying an ST-E2? I can get a used 550EX cheaper than the ST-E2, and I would have another flash to boot. Is there an advantage to having the ST-E2 over the 550EX on camera to trigger my 580EX off camera?

Unless size and weight are issues for you, I agree that the 550EX is the better buy than the ST-E2 for the reasons you cited. Plus the 550EX (and the 580EX II) lets you control the slave in manual mode and in three groups. The ST-E2 only does two and no manual control.

get the 550
it will be just a matter of time before you end up with a ST-E2 anyways, you'll eventually want to fire both flashes off-camera

PacAce wrote in post #8885752
Unless size and weight are issues for you, I agree that the 550EX is the better buy than the ST-E2 for the reasons you cited. Plus the 550EX (and the 580EX II) lets you control the slave in manual mode and in three groups. The ST-E2 only does two and no manual control.

Good points, I didn't know about the manual control.

SMP_Homer wrote in post #8885987
get the 550
it will be just a matter of time before you end up with a ST-E2 anyways, you'll eventually want to fire both flashes off-camera

Your probably right!

I came to this same conclusion and sold my ST-E2 - instead just getting a 3rd 580 EX II. Now, I have three full-featured/powered flashes with RF transmitters, or two full featured flashes that can be controlled through the camera.

It's a nice setup. I like the ST-E2 as well, it was smaller, but honestly when I'm setting up multiple flashes anyways, what does the size really matter? I also really like being able to control the flashes through the camera, that's nice to have.

ST-E2 is a fine piece of gear, but, at this stage of your development, the extra flash is certainly the way to go.