Gigabyte is having some issues here and there lately... Like they are kinda noisy
I personally feel that the majority of gamers here love msi and they have their reasons, though the asus is really good too, there's a tiny difference
You can buy either with no regrets, they are both cool and silent
If people slightly prefer msi there is a reason, but isn't big deal, the difference is so irrelevant that if you prefer you can even pick the video card by aesthetic beauty
I have ran many Gigabyte products, MB's.GPUs and otherwise. Not a single issue. I have also ran all the other brands as well. No major issues either.
For the record my pair of G1 970's are quiet and OC like a beast.