Just a couple points. I tried to install my MacOSX using a UFS filesystem. It broke many things to the point that it was unusable upon install. I had to reinstall with HFS+.

Second, I disagree about Aqua. It's slow right now, but from what I understand, this has to do with poor hardware acceleration support. Or did you mean that the basic UI is poor? If so, I'd have to disagree with that, as well, but that's much more subjective.