The Apple Menu is back on the left side compared to the Beta, but it functions more like the Special menu. Many shortcuts are missing however and I find that I have to use my mouse more that with 9.x. One of the things different from most 1.0 releases is the stability. MacOS X has been very stable. The Classic environment that runs MacOS 9.1 runs most applications, but there are some incompatibilities.
Most incompatibilities are from trying to access hardware directly.
MacOS X is not going to replace your desktop operating system right now. There are too many issues to be on everyone's desk. That is what me and my colleagues are doing right now. So, if you are the technical, curious, or adventurous type, in this case a very early adopter, go get your copy of X and have some fun. If you need to depend on that Mac for everyday work, we are advising waiting a little bit.