Earlier teething problems with the "Lindenhurst" chipsets are now sorted out, and there is now full PCI Express compliance.
I remember several years ago, when Athlon CPUs first came out. They were in slot as opposed to socket format, and a chipset to accomodate them was hurriedly rushed out. Of course, it was full of problems and performance issues, which was subsequently resolved in later chipsets. Sometimes, with hardware, its better to wait and see a new technology get established first, rather than reaching for that credit card right away, no matter how tempting that may be.