When Netflix first started their streaming service, using antiquated video transfers, I used to say that SD was lower than DVD, HD was somewhere between DVD and Blu-ray, closer to DVD. That is not the case nowadays in most situations.This is purely anecdotal but in my experience, streaming has a particularly difficult time with ancient SD masters. It’s fine when you’re streaming a new SD master made from a higher quality source, but streaming doesn’t seem to like old telecines. When I’ve rented old SD transfers on iTunes, they’ve always played worse than DVD versions of the same transfer.
I have the DVD and haven’t experienced any artifacts with it.