Anas Bashar :
what is your GPU? have one card or two? this PSU have two rails of +12V@20A.
for gaming PCs, a PSU with a huge single +12V rail is way much better, if not the only option.
and regarding the manufacturer, getting it from a well known PSU manufacturer is always better, like seasonic for example.
Nope, not true at all, not one bit. I wrote up a long post about this a couple years back, give it a read, you are quoting a lie that has been pushed out by the PSU manufacturers who make single rail units because its easier/cheaper(no multiple OCP). Trying to stop misinformation whereever it may arise.
http://www.tomshardware.com/forum/306437-28-single-rail-multiple-rails-eternal-question-answered
As for the question at hand, can you provide a link to where people are saying they had issues with MSI/Gigabyte boards with that PSU? The PSU can't tell what kind of board it is, and if it is complying with ATX spec it should work with all boards without issue. You can easily run two GTX 760s on a 650W PSU even with some OCing so im not worried about the capacity of that unit, it's series hasn't been reviewed yet so we don't know much about its capabilities but it seems to come with all the bells and whistles and a 10 year warranty which is surprisingly long so I'm not concerned about PSU quality.
Though I am still rather curious about what specific issues MSI and Gigabyte users were having, it may just be a couple bad units happen to land with non-EVGA boards and those people just made a louder fuss about it but im still intrigued.