I've seen this mentioned many times by users in the past. I may have used it at some point in the past, but in more recent years I began to use ColorMill in
VirtualDub. As of last year, I've started to use Adobe Premiere Pro CS4 for color correction, as it's even more accurate. Premiere has come a long way in the past 2-3 versions, making it a viable tool for certain features that had previously only been possible (or only done in good quality) by
VirtualDub and/or Avisynth.
Gradation Curves is definitely a decent VDub filter.