I got the 420EX flash and found that it is great. I took some photos and posted them but the response I got sort of hurt my feelings because they were blurry to the reviewer more so than to me. I decided to remove the topic I posted showing off my photos.
The comment I have about the flash is that it is great. Even if the photos I took came out blurry, I like controlling the light and how much brighter the flash is than the built-in flash.
So, overall I would say I absolutely love my flash. I don't think I will post my photos for a while at least not until I can take the feedback and right now I don't think I am ready. I really want to take fantastic photos but I don't.