5ghz wifi still broken on 10.10.3

I understand that Yosemite has wifi problems, and I believe those problems were supposed to be fixed in the 10.10.3 update, but I am still having issues on my 2012 retina macbook pro. I was wondering if anybody else is having these issues. let me explain what is going on first. I have a nighthawk x4 r7500 (i like it because it supports time machine) , and when I connect to the 5Ghz network, nothing can actually connect to the internet. In safari, a page will start to load, maybe even some images, but it always hangs. This will happen with anything that tries to use internet communications. I installed a fresh copy of Yosemite 10.10.3 with nothing else installed and the same problems persist. It even happens when i'm in the recovery partition for reinstalling OS X. I downgrade to maverick, and everything works like a champ. then upgrade again and the problem comes back. I have a friend with a 2013 rMBP and they don't have this issue. Nor have I found anybody else on the internet with this issue. So I was wondering if anybody on here is experiencing this and if they fixed it, then how. Note: the 2.4Ghz network does work, its just the 5Ghz that has the problems.