Your logic is wrong.
XP is the 5th
Vista is the 6th
7 is the 7th
Aren't they?
Odd < Even means Vista is better then both 7 and XP.
Odd > Even means XP and 7 are better then Vista, which is true.
Gah, No matter if it was just speculation but Vista and 7 were terrible, vista was rushed and tended to be missing much and when it was patched a majority of things were still missing and broken, same goes for seven apart from the rushed part, I'm really hoping Windows 8 atleast has some More Usefullness and compatibility then then the last two.