Ok, so what has changed since I went from 0606 to 0615!
During this process, because of a suggestion I got on that ASUS ROG forum, I have also been toying with a few different type of memory modules I have. Sadly, this yielded no different results then I had before, both on 0606 and on 0615, so I am convinced my memory is NOT the problem. Basically, using my default modules, or 2 other type of modules or NO modules make no difference whatsoever. Underclocked, default clock, default SPD or XMP profile (1600Mhz) also makes NO difference. I did these tests with both 0606 and 0615.
To do this testing I reinserted the BIOS battery and kept it in.
What 0615 changed for me is the following, when I now turn off my computer and take out the power and put it back in after 10 seconds, it will try to boot three times. The first time I can see the Q count running up but it turns off very quickly, sometimes even after a second, comes back on again, and often we're stuck at 00 again.
If I do the same but wait 30 seconds, the same process repeats itself, but especially the first try takes longer. Maybe it will even display the numbers running up the second automatic reboot, but most of the time it will still end up hung on the 00.
But, if I wait for 5 minutes and turn the computer on. It will try to reboot either 2 or 3 times, but the get through and come up with the BIOS telling me my overclock failed (Even when there is no overclock set!). If I then enter the bios, change nothing and save the settings and reboot. All is well, overclock or not. Mind you, this is with the BIOS battery inserted and it indeed does keep and remember my settings!
I have spent 2,5 hours yesterday to diagnose this, so I am quite certain in what is and what isn't happening. Trying the clear CMOS button was never enough, it needs the power to be disconnected for a certain amount of time. Also, without the battery, the original trick is still working, but does erase your BIOS and settings.
So progress! Now, I can at least keep the BIOS battery in and it does indeed remember my configuration. It just won't boot when you disconnect the power and reconnect it "too soon", meaning, within 30 seconds or 1 minute. But when I started using a 5 minute period, the results would consistently be the same. I would POST, overclock failed, apply to configuration it remembers and boot, it works every time.
So things are progressing! This is already a lot more workable then it was before.
One thing to note, when using the Intel RAID, if you switch it from RAID to AHCI (or your motherboard does this because it resets itself, etc.) and back to RAID again, one of my RAID-0 sets would come up as failed. In reality, there was nothing wrong with it, but there is no way to recover it using the Intel tools. I have found a way which I will write an article about soon, so that others facing this problem don't have to stress too much.