kmod-nvidia or dkms?

[Ed Greshko]

I've just installed F15 x86_64 and have been trying my best to use the 
nouveau driver.  However, it is falling short.  I could probably live 
with the failures in some of the "desktop effects" in KDE.  But, the one 
I can't seem to accept is the inability run GNOME 3 in a Vbox guest.  In 
F11 to get this running, I had the nVidia drivers loaded and checked 
enable 3D support in Vbox.  Worked fine.  As it is, the Vbox guest 
crashes when starting GNOME.  It "quarter" works with KDE....  No 
crash....but lousy rendering.

When I was using F11 I used the dkms method because I wanted retain the 
same nVidia version and still not worry about kernel updates.

I'm thinking of changing to the kmod method from rpmfusion.  Has anyone 
gone this route with F15?  Any gotchas or things their install misses?  
Works out of the box?

Thanks,
Ed