I've only had to RMA 3 boards in 10 years.
1st was an Abit, but that's moot now. Nonetheless the RMA was smooth.
2nd was a Gigabyte 965-DS3, took quite a few emails, but once the RMA was approved I got a replacement in reasonable time.
3rd was a buddy's EVGA, forget the model, one of the Nvidia chipsets, RMA and the process was easy, smooth, and pretty quick.
Take from that what you will.