I'm familiar with the first three Zeitgeist films, as well as the Venus Project. They do highlight some important issues, but I don't really agree with their proposed solutions -- I would even go as far as to say that a lot of their thinking is deeply flawed as far as solutions go. Essentially, what they propose is a technocratic communist state that is wedded to the ideology of scientism. It's a very top-down approach that would likely lead to a dystopian nightmare similar to the sort depicted in the film 'The Giver'. I don't like the idea of authoritarian scientists making decisions without public consent on every aspect of human life.
I really respect Jacque Fresco as an educator, innovator and public speaker, but I honestly can't see how a resource based economy would work at a practical level. Human nature is such that there are always people who want more than their share -- all you need is one bad egg for the whole system to fall apart.
Another thing I don't like about the Venus Project is the materialist lense through which they tend to see everything through (I mean 'materialist' in a philosophical sense, not a wealth sense). This is a very reductionist, and dare I say Marxist view of life that sees the whole of existence as just a bunch of colliding atoms that just need to be bent to the will of humanity in some perfect social arrangement somehow.
Although I am not religious in the conventional sense, the Venus Project dismisses philosophical, aesthetic and 'spiritual' aspects of life out of hand. I think this is a huge mistake on their part. There are some great design ideas proposed by Jacque, but it's a politically naive and flawed project.