I went to the 2013 TT and was overall amazed by the good behaviour of everyone I saw or met. I found it a very friendly experience so reading the odd posts about worsening behaviour was interesting. Only real concerning things I saw over there was incredibly dangerous riding at times - not just over the mountain, and spectators drinking while watching the racing and then riding off after racing was finished. I love a beer or two but won't drink and ride - it may have just been an odd few doing it but it was noticeable.