I personally did not like the System, I found it really hard to learn, it was the first disc I was learning from. I have learnt nothing from it and it has gotten dusty...
When people were recommending the Trilogy, I was a bit worried of purchasing it as I thought it was just going to be a longer version of it, and not taught very well (sorry but I really do not think the System is taught well at all).
I am glad I have purchased the Trilogy, as I use it quite a lot for practising, and it is much easier to learn from. So, this is a DVD I would recommend to anyone.