Oh, it's really very good. Amongst its many talents, it allows the watching of videos where streaming isn't possible (e.g. old machines or poor internet connections). New features are thoughtfully added, bugs addressed, and it's totally free if you are a Linux user. Hurray!
Further down the line, this review still holds true... Thanks, mig
Even further down the line (late 2020), VDH is still helping me to reduce my environmental impact by using old machines that others retire as 'unusable' and using VDH to download once rather than streaming repeatedly and jerkily.