Hi /p/

I am new to club photography and want to purchase canon speedlite 580ex ii. What is the difference between 580ex and 580ex ii. Should i pay extra for the latter version? at the moment i am shooting with 400d but by the end of the sumer will purchase 5d mk2. as well as club photography would like to take snaps of corporate events. so far i have been shooting using onboard flash that came with my camera but not entirely happy with the results. i feel the colors on the pictures are burned out would like to have more control over the light. picture is relates, this is the picture ive taken in my local student bar.

thanks