I am the actual hands on builder/GC, and the homeowner. I've been a builder for about 15 years and I'm sort of tired of stick framing.

I considered both ICS-SIP out of NC and The Murus Company, in Mansfield PA. Both were east coast manufacturers of polyurethane sips. THey both seemed good. I went with Murus because it was more local (in state).

I'm building a 3 story building. The 12' high panels were a little tricky to work with. The 10' and shorter panels just flew up. You should know that there is structural framing within the SIPs that you'll have to consider for headers and such. THe SIP manufacturer will spec that out for you.

I went with a conventionally framed roof because of the very low slope. If there was a roof leak I would never know until the structural integrity of the panel was compromised. If I used a greater slope I would have gone with sips.

sipweb.com is a good resource and has a forum to ask questions.

I built a pole barn house that used SPF in the walls and floor.  Roof was staggered layers of batt insulation.  I agree one should design for technology to be used.  SPF is much more forgiving than SIPS (re leveling, gaps,) and is fast.   Most importantly for me is IT IS STRUCTURAL so I needed no plywood.  Simply put up the 1 x 8 vertical boards and sprayed.  Because of the pole barn design the horizontal nailers were 2 feet o.c. horizontal on the outside of the poles which eliminates any thermal breaks except for the poles which had an inch sprayed over the interiuor anyway because they weren't exposed finish surfaces. . .Interior walls hung off the box beam.  SPF is more flexible in insulating risers, septic pipes, and well risers if the house is on piers, which pole houses are.  Blue board invites some insects. Another house I did was conventional 2 x 6 stick with batts, then 1" high r-sheathing on inside with glued 6 mil plastic.  Then a free standing 2 x 4 2' o.c. with a 1" chase for plumbing runs on exterior walls.  (mice like it too though).  Mixed insulation systems seem to work best for me as SIPS don't work well beneath the pier construction system.  Good luck