mixing unstable with testing just for nvidia: good practices?

["H.S." <hs.samix@gmail.com>]

Hello,

Yesterday I made the jump and put in unstable sources in sources.list in 
on testing machine solely to get nvidia working again in Testing (what 
is wrong with testing regarding nvidia anyway?).

I have this for my policy:
$> cat /etc/apt/apt.conf
APT::Authentication::TrustCDROM "true";
Acquire::::Proxy "false";
APT::Default-Release "testing";


Is this good enough for an "aptitude update" and "aptitude safe-upgrade" 
such that only those package will be pulled from Unstable which are 
necessary for nvidia related packages? Or should I now just remove the 
unstable sources' repos from my sources.list file?

Recommendations and advice on what is the sensible way to proceed in 
this are welcome.

thanks,
->HS