Upload & Sell: Off
way too many issues with bad capacitors on young nuo flashes.
+1...I have three 580EX II's and all have performed 100% reliably under very stressful shooting. I recently purchased a manual Yongnuo (model 560 I think) as an ER back-up and for some remote camera operation. The first thing that I noticed is that the plastic housing feels inferior to the Canon...that would be indicative that everything else is of inferior quality as well. When I was looking to buy a used one (here on FM & on POTN) I came across several offers with broken or partially functioning units. In fact, one person sent me his broken 560 for free just for spare parts. Also, I have read a number of posts stating that the Yongnuo flash has failed within a year or so. I have no idea what the real-world percentage numbers are, but it seems to me that there is an extrememly small failure rate among the Canon OEM Speedlites and a higher rate among the Yongnuo's.
I'm sure lot's of people have purchased a Yongnuo flash and are happy with it...I'm not saying it's a bad value for the money, but it may not be good enough for critical shooting when you really can't be worrying about flash failure. Any flash can & will fail eventually but with my Canon's, I don't worry about it and I always have a back-up. If I only had Yongnuo's, then I'd be worried every time.
My 2 cents: If you shoot critically and need 100% reliability, then choose the real Canon...it's better quality all around. If you don't need such critical reliability or simply want an ER back-up, then the Yongnuo is probably a good cheap alternative.