Sadly, I disagree with you - from my own experience and that of others.
On my own, I assembled a monster of a PC using i7-6850k CPU and Asus ROG Strix X99 Gaming motherboard - thinking like you that Asus as a brand would not have any issues with their premium/gaming boards.
I was sorely mistaken. Not only did the board die within less than a month, it took my CPU with it. I had to RMA the CPU, and after talking to asus, they also RMA'd my board on the spot (instead of sending it to taiwan to be repaired). However, the saga did not end there, and after a 10 day vacation recently, I've came back to encounter other issues which turned out to point to faulty RAM slots (not the RAM itself, but the slots on the brand new replaced motherboard).
I have also went on newegg and checked people's reviews about Asus X99 based motherboards - it seems that many of them share the same issues!
So, better steer clear and try Asrock or Gigabyte instead. Even MSI got issues with their x99 gaming boards.
villrein :
I've never had a modern ASUS board go wrong on me and would recommend them myself. I have used X79 and X99 Rampage and Sabertooth boards and they are built to a high standard and have never failed me. It pays motherboard manufacturers to make their boards reliable because of the considerable cost to them of warranty claims, so I wouldn't worry about reliability too much with ASUS, Gigabyte, ASROCK and to a lesser extent msi (though I've just bought an msi X99a Sli Krait board with a 3 year warranty myself as a backup board, so I trust msi and their warranty claim procedures too).