Digital Vibrance is just a fancy word for gamma, color and brightness correction. Any decent video card from ATI or Nvidia can get the same results. If you already have a Geforce4 MX440 it will do a good job. However, if your are buying new, there is only $10 difference between the MX440 and the Radeon 9000.
The 9000 is much faster when overclocked to 9000 Pro levels, fully supports DirectX 8.1 hardware, and has better 2D and 3D image quality. When you add the DVI connection, the 9000 can be had for $71 shipped and the MX440 goes for (cough) $77! Also when you are using a quality LCD monitor the DVI option on Nvidia cards makes little improvement over the analog connection. The hardware specs on the DVI intput are not up to par with ATI's. This is a known issue with Geforce 2 and Geforce 3 chipsets, perhaps Nvidia corrected the shortcoming on the Geforce 4, since I don't have one I can't comment on that.