UPDATE: After over 2 years of using VDH on macOS, I find that not enough attention has been paid to making it run well on the Mac platform, especially in YouTube. It can be difficult to tell whether or not you are downloading the audio or video portion. You'll have to pay $30 to get your videos aggregated (audio and video combined) or else take extra steps after download to combine the audio and video. And then it will also have a QR Code image in the top right corner! If you download from YouTube a lot, then there is a better extension for you [Easy YouTube Downloader] that will download the video aggregated (with audio and video together) in one click at 720p (high quality) for free.

Original Review:
VDH 7.2 works well on Firefox 58.0.2 running on macOS Sierra 10.12.6.. Although not every feature has returned to the Web Extension from its legacy days. But the developers are working on it! Most features you would use are available. Mig, the author, is very responsive on the forums when he is not busy programming to update and fix issues. He has a positive attitude, is good-natured, and is genuinely trying to get the best version of this web extension to us as fast as he can. Please be patient and don't abuse him as he gets VDH on track. I found that some of my issues were not VDH's fault but rather caused by the tracker blocking features of the new Firefox. For me everything has worked very well except downloading some DASH videos that would not aggregate. This issue has improved with the frequent new releases of the Web Extension as mig copes with the restrictions on the code created by Firefox Quantum. This Web Extension is a job well-done and I recommend it.