As a source of information, I might give Wikipedia 2 or 3 stars. They do have an extensive collection, but certainly not everything. But, the quality of writing in ways that make the information accessible to anyone is very inconsistent. The authors (and Wikipedia should encourage this) should link to external sites for more technical content.
I just tried posting a set of 4 interrelated pages. And, I'm already screaming and thinking about posting elsewhere.
1. The whole interface is obtuse and far more difficult than it needs to be.
2. Instructions are often wrong (e.g., they say to click on "Save Page" when there is no such button or link) or incomplete (they say to do so and so, but they give you no clue as to where to do this).
3. To get help, you have to go through this completely ridiculous process of posting a question. Why not just have a forum in the typical forum format? Why make it so difficult? It took me 6 tries to get a question posted.
4. They should have all of their instructions and taboos posted in a one simple to access and read area. But, no... they make you dig for it, just guess, or find out the hard way when they reject a page.
5. There should be a way to easily communicate with one individual who made a decision to reject so that you have a consistent way of making changes.
I've worked extensively on Wikidot sites and with their forum. There is a night and day difference. I just find Wikipedia to be frustrating in all aspects from the posting angle, and, I'm not sure how to express this, but there is some deeply embedded ignorance/stupidity or arrogance that prevents them from doing something other than a giant framework of obsolescence. Some group needs to do something better and push out Wikipedia.