Hi All, once again I come for your advice. I just got my 5D Mark III to go along w/my 5D Mark II. There's still a few items I need (such as a grip for the MK III--I much prefer a grip as my MK II already has one), but of immediate need, I feel is another flash...a stronger flash! I currently have only the 430 EX II. I've been looking at the refurbished Canon 600 EX-RT offered by the Canon store for $440, but it's out of stock. I'm also looking at the YN 568 EX II. Any of you have any positive experiences with 3rd party flashes? If so, which one in particular do you recommend? Thanks!!