They are using piggyback fuel management for the kit for the Si. Compared to their past kits, the new kit for the 06 Si is supposed to be a major step up in component quality. I've read they are also allowing you to customize your choice in some of the components as well.
I have not read good things about piggyback fuel management.
http://www.team-integra.net/sections...?ArticleID=181 has a good article on ECU's, and I believe is where I read about the piggyback fuel mgmt.