I have had this board for a few weeks now (with 4790K), so I thought I would share my experience with it.
So far, it is my least favourite board I have ever owned!
I have had so many problems with it - though I do believe most are down to the BIOS. Have landed up with corrupt data, and other various problems.
Anything from the F4 through F6B BIOS have been terrible.
Apart from data corruption, there have been other things like having an OC stable at 4.75GHz with 1.28V for days, only for it to suddenly become completely unstable. Can no longer OC to the same level, and whether or not I can run my Kingston beast 2400MHz ram is dependant on BIOS - currently having to run it 2200.
F2 and F3 appear more stable, but seems to require more volts - and to be honest, I paid over the odds for this board for support and updates, so hopefully I won't be stuck on those due to issues with later BIOS.
Performance seems to be lacking a bit. I score lower in benches than people on 4470K at similar clocks.
I understand the PLX chip will mean I won't get the same graphics performance as someone on say a X79 platform, but performance with 3 x R9 290 has been underwhelming.
I hope they get their act together with this board and release a stellar BIOS that sorts most of it's issues, but as it stands I am not a happy customer.