Canon 20D & Flash

[Kantankerous]

Hi guys, I'm looking to buy an external flash unit and read various reviews in regards to whether or not I should go with the 430EX (I and II) or 580EX (I and II) range. Price is not a huge factor but I'd like to weigh up the pros and cons of what each external flash has to offer.

From what I've heard is that the 580EX II seems to be giving off inconsistent results with the 20D unless used on manual mode and being a newbie, I'm not sure whether or not it's the best place to start. Having said that, I've been recommended a few times to go with the 430EX range simply because I'm just starting out, however is it ideal or will I end up regretting not going for the 580 range?

Also because the 20D is a relatively old body, I'm a little worried about the flash heating up too easily with the more powerful flash units but because I haven't used one before I'm not sure how much that will affect me. So if you guys could help point me in the right direction that'd be great!

Thanks,
Kan

[Samanax]

What kind of photography are you doing now? And will you only use the flash on-camera or do you plan to use it off-camera as well?

The 580EX (I or II) would be the better of the two choice just because it offers more.

[Kantankerous]

It'll be predominantly on-camera as I tend to do a lot of outdoor shooting, in particular low light environments. But I'm still tentative about whether or not the 580EX is going to be too strong for my 20D to handle? I don't know if that's true or not considering the 20D can only take 6V from the hotshoe.