Still capturing DV nowadays, is indeed a step backward...When you still live in the past use software (and hardware) of the past like VP17, no direct need to upgrade to Vp20. Also VP17 and VP20 could live and work together on your probably ancient PC, but don't expect that your PC support Magix GPU supported AVC encoding.
A recent PC doesn't have the needed firewire connection, why should a recent NLE have then a firewire capture feature?
I wouldn't consider an 8 core AMD with 64GB ram with a Quadro graphics an ancient computer, that runs the latest version of Avid Media Composer ready for the dust bin. I am archiving probably a hundred DV and HDV that were originally outputted to Blu-ray or DVD, and I had found Vegas a quick tool for that purpose.
I found the stand alone Vegas app Vidcap60.exe and installed that as a shortcut.
As the Vp20 help files indicated IEE capture was supported and the VP20 capture pop up showed "DV camera" as one of the options for capture perhaps you might understand my irritation.