Most of us swear at the ADVC units. While they proclaim to have TBCs, there's generally no observable effects from it -- which isn't the desired function of a TBC. Additionally, in the NTSC domain, it crushes the colorspace of incoming VHS 4:2:2 (comparable) video to 4:1:1, distorting color and detail in the process.
DV was made for shooting, not converting.
Some people like the units because they're easy to use (basic dummy-friendly boxes), but that still doesn't change the fact that it's not doing a very good conversion job. It's butchering the video just as much as it's transferring it. Better hardware will correct the video -- not just say it does (and then not).
Thanks for writing.