It might have had a good performance but it had lots of other problems. It was hot and prone to overheating etc.
I hope they've improved their overall CPU designs now. The biggest problem for AMD (IMO) is that they are so far behind in process technology. They'll come with 32 nm just when Intel releases 22 nm. If AMD manages to close that gap or at least reduce it to 6 months they might be able to finally compete with Intel and make profit.