I can't comment on the other 2 (owned the brands, but not the specific models) but the EA500s I've used have all been virtually silent. I assume that if you push them close to their limit the fan will spin up and be noisy, probably louder than the other fans, but otherwise the EA500 is very quiet. At this point I have used 4 of them in builds and they have all been great.
EDIT* To be more specific I used to run my e8400 @ 3.8 with a 4870, 3 HDD's, 8GB, etc... on the EA500 and it never spun up enough to be audible, at least not that I ever noticed and my build was virtually silent. I also had one that made an intermittent high whine (brand new, but had been in it's box for 2 years) so I called up Antec and without any hesitation they sent me a new one. I'm sure XFX and Corsair have great service, I just have had experience with Antecs and found it pleasing.