Bests & Worsts Reviews from Amazon

I am a beginner to SLR flash photography, and I spent several weeks researching various flashes, both by online reviews, and by going down to the local camera shop with my Canon 350D (Rebel XT in US), and I finally decided on the 430EX over the Canon 420EX, Canon 580EX, and Sigma 500ST Super for a few reasons: 1. Manual Control- Not only does this give you the obvious ability to have more creative flexibility, but as a beginner, it gives you the opportunity to experiment, and practice the more technical skills of flash photography. Another benefit of manual mode is the ability to use opitcally triggered slave flash units in a multi-light setup. Fully automatic E-ttl mode flash will trigger the slaves with the metering preflash, and make using optical slaves impossible while using the onboard flash. (there are work arounds, but they involve reducing the output of the onboard flash to a minimal level by FEC or covering the flash with something, limiting your flexibilty in creating a lighting setup). This manual flexibilty was the primary reason I choose the 430EX over the 420EX. 2. Remarkable recycle times. I have no scientific data for this, just subjective feel. The 430EX out-performed the 420EX here. Not by a huge amount, but it was noticable. Under the same conditions-bounce for fill, low ambient light (meter read .3 sec at f4), the 430EX would be able to fire off an extra few shots in succession without having to wait for recycling. Depending on the battery level I could get 3 to 5 more partial power fill flashes in low ambient light, pressing the shutter release quickly with the 430EX over the 420EX. Again, not a huge difference, but noticeable. 3. Build quality was better than the Sigma. I use my camera a lot, in the most hostile of camera environments (I am an elementary school teacher) and it swings around and bangs into things, and gets swung around and banged into things...etc. The build quility compared to the Sigma isn't that different for a casual user, who will take pictures at home, or in a more controlled environment. In particular, the Sigma battery door felt weak. This wasn't a decision point for me, but it helped me lean towards my decision. 4. Finally, the last factor was the ability to function as a slave in a wireless setup that isn't optical. Optical slave setups are great for experimenting, and studio type setups, when you have the only camera in the room. But they do not work when every mother and father is taking a picture at the school play, and in the future, I plan to upgrade/expand to include infared control of a flash setup. Again, there are other options for non-optically controlled slaves, but the 580EX plus Canon slaves is an easy way for a non-pro like me to go. For me, the primary selling point was manual control. I probably would have gotten the 580EX otherwise, and just might do so in the future if I can save my pennies. The Sigma 500ST Super was very tempting as well, and if you want a powerful flash, manual control, and don't plan to use a multi-flash setup, or you use an optically triggered setup, I would recommend that flash highly as well. One last point, the AF assist on the Canon flashes will cover all the focus points on a 350D (Rebel XT), and 20D, whereas the Sigma will only illuminate the center AF reliably. This AF assist is much nicer than the built in flash assist, and has a reasonable range for most portraits and group shots in low light. I hope this review helps you! It took me a long time and lots of research to decide, and hopefully, I have presented my reasons in an intelligible manner! Have fun and take lots of pictures!