After using the restricted Nvidia driver on my Dell M1330 laptop I got very big fonts (first I thought there's something wrong with the resolution). I solved this by forcing the font DPI:
Go to 'System Settings' => 'Appearance' => 'Fonts' => 'Force Fonts DPI' => Choose 96 DPI.
Go to 'System Settings' => 'Appearance' => 'Fonts' => 'Force Fonts DPI' => Choose 96 DPI.