I have an ADVC and it works great, can"t speak for the DAC though as I don't have one.
I f I was buying a new one though I might be tempted by an Elgato device or any converter with a tv tuner in it so i could have my own PVR.
MacWorld gave the DAV-100 it's editor's choice in a review of about 4 different Analog to Digital units. I was looking to get one of those myself but I just bought a DV camcorder that also can be used as a converter. The DAC-100 works bi-directionally if you want to put stuff back onto analog tapes. That was one of the selling points for me.