Has anyone tried it, or had any experience with it? Thoughts in general? Wiki here: http://en.wikipedia.org/wiki/Shingon_Buddhism . 

There's a talk which includes Hokai Sobel's description of Shingon Buddhism:

http://integrateddaniel.info/podcasts-and-videos/

Was going to link this, but you beat me to it.  Hokai is a Shingon practitioner. From what little I understand, Shingon involves more rituals and mythology in meditation practice than other branches of Buddhism. This is of course not a bad thing, I think it makes meditation more enjoyable. 

may you also find value in here about the topic from Shinzen Young
(as he was ordained as a monk in Shingon tradition)

http://www.shinzen.org/
http://www.buddhistgeeks.com/author/shinzen-young/