I work as an assistant architect and just had a recent education of SIP's. As far as I can tell they are a really great product. They cut down on construction time. They have a higher insulating (R-value) rating than a wood stud wall. In fact a 4" SIP has a higher R-value than a 6" wood stud wall. They have pre-drilled holes in them for electrical wiring, which is truly an electrician's dream (no more "fishing"). You can even build your roof out of SIP's.
I would recommend you go to this web-site which has a lot of information and request a literature packet. www.thermalfoams.com
I live in the Buffalo, NY area. If you live in this vicinity, Thermalfoams has offices in Buffalo, Rochester and Syracuse, NY. The representative that I spoke with was great and so helpful. If you live elsewhere I am sure the web-site can direct you to a local rep.