I disagree with that. I like the Mac OS UI, it's clever and straightforward, it doesn't get in the way, the search tool and smart folders work well, the backup mechanism is smart - everything's just so much more cohesive and considered than it is Windows.
Windows also still has fundamental problems like the cruft-ridden registry, a complete reliance on the old hierarchical file/folder thing, after a few years those little gripes get really frustrating.
I don't know if a few years of Mac OS will leave me equally frustrated, maybe so, but in the meantime it will be a breath of fresh air.