I'm sure Scan could contribute, but returns is far too complex a subject to just boil down to a simple number and publishing returns figures would be opening a complete bag of worms probably for no real benefit to anyone.
Reliability is usually pretty good on computer parts. Even my old OCZ SSD which is probably well into the "Infamous" category for reliability works fine. Far more important is how a company deals with problems when they arise.
Last time I tried to use the Asus support it was a pretty bad experience. Thankfully I have found it rare that I had to use it. Their boards have been either dead on arrival or just work, BIOS updates tend to be quite frequent. I have a few Gigabyte boards, they make for a noisy computer with over aggressive fans, and I don't like the BIOS. The Gigabyte range of choice is just better though, looking for an ITX socket FM2+ board recently I couldn't find an Asus one so it basically came down to MSI vs Gigabyte.