I had random BSODs about 2 or 3 times per day with bios F7. No memtest86 errors at all (tested thoroughly). Gigabyte support suggested that I used F8a, so I did, but that didn't solve the problem. I decided I'd try to learn to live with the BSODs, after all, this build boots up in seconds and I'd just have to save my work more frequently. Eventually it got annoying so I decided to use only 2 of my 4 RAM sticks. With 2 sticks, the system was 100% stable and there's no noticeable performance difference between using 32Gb and 16Gb for the type of work that I do (photoshop). I did increase the CPU System Agent Voltage by 0,2v or something like that cause I read somewhere that using 4 sticks could benefit of doing so.
I have a 4770K, the Z87X-UD5H and 32Gb of TridentX at 2400Mhz CL10.
So you say that there's a new beta BIOS F8c. Let me ask something, did you have problems with F8a and now with F8c they're solved? That would be fenomenal.