Originally posted by: Denithor
Welcome to the forums!
The correct answer really depends on your current needs. If your 3200/6800 still meets your needs, to put it simply, don't upgrade. Even for a free card.
And if you do need to upgrade, you're going to want better than an old 7800GT for your new rig. Seriously, you can buy a 4670 these days for $60 or less (after rebate) that will smack around the 7800GT like a bad habit.