What use would vista have on a vista/win 7 dualboot PC?

[Winsanity]

Is there any need for windows vista dualbooted on a PC with Windows 7? My friend was a diehard XP user who never even thought of the idea of using vista/win7 before his old dell died(he didn't wanna use them not because his system was old it was because he thought they were shit). To me it sounds like a waste of space since windows 7 supports everything vista does while performing as fast as XP. I want people's opinions on the matter. Thanks.

[Panda X]

Purpose of Vista on a Vista/7 d-boot:

1.
2.
3.

[Winsanity]

[QUOTE=Panda X;18977192]Purpose of Vista on a Vista/7 d-boot:

1.
2.
3.[/QUOTE]

Thats everything I wanted to hear thanks.