I have, and so has a close relative of mine who is a structural engineer, and went to some dumb presentation on building #7. A lot of stuff happened that was strange, but passenger planes flew into skyscrapers that came careening down, not a common occurence that can have predictable results. Overall his conclusion was that a lot of their 'evidence' was founded in pseudo-science that falls apart under professional review.
Also, from a different perspective, what would the government have to gain from pulling that off? resource acquisition and military contracts are the retort, but we've invaded Afghanistan because of 9/11 and their natural resources consist of Pomegranites, pistachios and some minerals, nothing that valuable. We already occupied most of the world, the government didn't need 9/11. Contractors already got what they wanted from all the lobbying they do.
lastly, how can anyone who believes in 9/11 truth support Ron Paul? If you believe there is that massive a beauracracy capable of hiding this from the world, you would have to believe massive beauracracy works, which is counter to libertarianisms core