It is a bit difficult, since the SpinWatch website's right to free speech is under attack, as of two days ago, which is the more important thing.
But since you ask, I think the project is flawed. The editor David Miller is a petty sectarian, whose site masquerades as an objective wikipedia style encyclopedia of corporate spin, but mere centimetres below the surface his own crazed prejudices - against other left-wing factions, about the secret networks running the world (Bilderberg and so on), about the Jewish influence behind neoconservatism - keep popping out.
I am probably a bit biased because his site accuses me of adopting views to curry favour with corporate interests, which is irritating and untrue, and he publishes details about friends of mine's political activities along with details of their employment, which seems to me to be calculated to cause trouble for them with their employers. SpinWatch is what Campus Watch would look like if it was run by the Spartacists.
Anyway, I guess he is entitled to his cornpone opinions, just like Ward Churchill or Vandana Shiva, so he should not be censored by Britain's excessive libel laws.