Have you tested the 580 EX II with the new PW TTL system? I have, and it's pretty inconsistent. I have been much happier with the 430 EX II flashes. (I have the 550, 580, 580 II, and 430 II flashes.) In fact I am considering selling my 580EX II flashes for some more 430 EX II.
I don't mean to hijack your sales thread. The original 580 is one of my favorites -- great flash. Hope you sell it quickly.
I've read the problems people were having and PW just updated their system with new firmware. The problems people were having, mostly, is that the 580EX II has a noisy RF signal. So when a 580 EX II is mounted ON TOP of the PW transceiver, the distance can be greatly reduced, like down to 30-40 feet or so. If you use the transceiver as a master w/o the flash on top, you get the full distance.
I really did think about the 430EX II but I don't like how the head works on that flash. And the price is only 150.00 US less per flash. That 450.00 more for three flashes, but then you get more power and functionality. If I get to a place where I'm needing more than three flash guns, I'll probably go with 430s for sure. I could maybe go with one 580EX II and 430s. Then I would save 300 US. But the 300 just isn't enough to sway me to them.
But I really haven't done a side by side comparison between the 580EX and the 580EX II. What would you miss not having a 580 EX II compared to the 580EX?
I'm really serious about moving to these flash guns for commercial work--non studio, non high end portraiture. Once you get a feel, and I say 'feel,' for the Canon flash system, it's just too fast and easy to not use them, especially for things like car photography, since their footprint is just simply minimal.
Thanks for bringing this up again.