Ubuntu is a better starting point for Mac users. They will immediately feel comfortable there. I am not sure there is any distro that can do that for a Windows user. Mandriva is close though, closer than Ubuntu.
The software is nicely presented in Ubuntu though, solving the first problem every new Linux user has - so it is a tough call
But Linux must be Linux - not a sorry Windows or Mac copy. I think we are on the same page there.
Ease of use and an immediate positive experience, is important IMO.
For that the Windows lookalike trick might work - but yes it is cheating

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