The reason why you only see posts with problems is because the MANY owners of this board with no problems do not come to forums like this to post. Of the posts that you see here, MANY of them are the USER NOT the manufacturer! You need to read between the lines with these message boards. For example I saw a thread on here that said "A8N-SLI Problems w/ mobo" or something like that. When you read the thread towards the end, the guy forgot to plug in the 4 port plug from the psu!
Having said that, I have had zero/nada problems with this board, and I'm not surprised at all. After all, it's an Asus! It was the EASIEST installation I've EVER performed! Everything went together straight out of the box. Within 3 hours of getting this in the mail, I was gaming using SLI mode, and getting benchmarks that I've NEVER experienced that high! This is the BEST and FASTEST motherboard I have EVER OWNED, and I've owned MANY boards! I also believe that this is the BEST motherboard available on the market today.
So to answer your question, YES there is a happy a8n-sli owner, and I couldn't be happier or more satisfied. And believe me, there are many, many more.