It doesn't run flawlessly, there is no such thing whether it's beta or final. I am running it on my iMac and I agree, it's running a lot better than I thought it would. Nothing has really prevented me from using it, at all. A couple applications have crashed, but nothing too serious.
I am excited for the next Beta version for the Public and/or the final version in the fall so we can really take advantage of it's real features missing currently.