Ever since I have announced the Canon 580ii / 430ii Speedlite Crash Course DVD, Ive been getting a lot of questions on which is a better buy and what the differences are. If you look around, you can find the 580ii for less than $400. Is the extra $70-100 worth it? In my opinion, ABSOLUTELY. If it means waiting a little longer, do it. Now, if you are someone that already owns a 430ii, let me say its a great little flash, and you are in luck, its completely compatible with the 580ii as a slave unit. If you are going to do any amount of professional work, you will need at minimum 2 flash units, (3 for good measure).

Here is a comparison of their features for your consideration:

Model
Current Price (BH Photo)
Max Range
Top Recycle Time
Built in Transmitter
Built in Receiver
Battery Pack Terminal
PC Terminal (For Pocket Wizards)
Catch Light Panel
External Metering Sensor
Custom Settings
Strobscopic As Single Unit
External Flash Metering
Weight
580ii Speedlite
$420
58m @ 105mm
.1s
Yes
Yes
Yes
Yes
Yes
Yes
14 w 32 settings
Yes
Yes
405g
430ii
$330
43m @ 105mm
~3.0s (!!)
No
Yes
No
No
No
No
9 with 20 settings
No
No
320 g