Have a VHS DV capture I'm eventually going to convert to 16:9 Blu-Ray.

I'm going to do noise reduction on a 59.97 Huffyuv file with NeatVideo. Does it matter at what point I convert to a 960 x 720 4:3 image inside a 1280 x 720? If I do noise reduction and sharpening on a smaller 720x480 Huffyuv file and wait until the last stage to upconvert to HD size, will it make any difference in the eventual quality? Things will go a lot faster if the computer is chewing on a smaller image to do noise reduction than a larger one.