It's become cliche to hate on Wu these days, so I take a lot of Wu criticisms with a grain of salt from alleged Wu-Tang fans.
They still pump better albums than a good portion of the hip-hop game. Like all groups that have as much longevity as Wu-Tang, they have their share of bad material. But they have much more good than bad.
Only Built 4 Cuban Linx 2, for example, was one of the top albums of last year in terms of quality (and sales, relative to it's mainstream promotion). The ficalness of most "Wu fans" has led me to believe that many are more interested in the behind the scene stuff, rather than the actual music itself. I strongly suspect that a lot of criticisms for 8 Diagrams (which is still a great album, and 3rd best group effort from them in my opinion) wouldn't exist if it was reported they were all happy with the finished product. But, unfortunately, many "Wu fans" want to get caught up with picking a team (i.e. Team Raekwon, Team Ghostface, Team RZA, etc).
In any event, I'm looking forward to this documentary.