Both sets of the DVDs are pretty well made, with clear video and good angles for viewing what they show.
While I'm sure the YZD DVDs are excellent if you understand the Chinese being spoken by YZD, if, like me, you don't understand Chinese (Mandarin I believe) then you have to rely on the English translator.
While I'm greatful for the translator, don't get me wrong, the translations leave more than a little to be desired.
For instance, on the Saber DVD there is a point where YZD is showing something, it is quite clearly an extremely important point as he talks about it at some length, holding the saber, pointing at it, moving it around in various ways, going back and remaking the point at least twice, the translator remains totally silent throughout.
THEN, just as YZD is beginning to move on, the translator says, and I quote, "Do it this way, that will be good."
Leaving me to shout at my television, "WHAT WAY? What will be good?" every single time I see it.
This is only one example, this happens quite a lot.
On the other hand, Yang Jun speaks English throughout his DVD sets. All of them are excellent, clear, easy to understand and follow.
I have the Hand Form and Push Hands DVDs so far, and I have borrowed both Sword and Saber recently so I am familiar with those as well.
These are top notch DVD's, professionaly made, nice clear video and easy to understand and follow instructions.
There are some minor points of difference in the form work. Yang Jun demonstrates the forms on both sets of DVD's and there are some clear, albeit minor, differences between them in the forms.
There is about twenty years in between them, so that's not too terribly surprising.
The largest difference I have seen is on Fair Lady Works Shuttles. I've noticed this as well in between the Saber DVD's, there is the same difference in execution of the form on the saber form that looks remarkably like Fair Lady (at this morment I am completely brain dead on the saber form name for some reason).
All of the differences are minor, very small changes in form presentation. I have no idea if this reflects differences in how Yang Jun does his form as compared to how YZD does his, or if it simply reflects the changes over about two decades to the form of Yang Jun.
Either way, IMPHO, you get quality DVD's for your money.
Hope this helps.