You are talking about ICF(Insulated Concrete Forms). The advantage of these is you can set up the forms yourself. At this point this construction method is more expensive the standard wood framing. Plus, you still need to frame out around the windows and the doors. The floors are still built conventionally. The only thing that would concern me in Maine is the potentially for carpenter ants to nest in the outer panel of foam insulation.
Keep in mind, heat rises from natural convection. Therefore, most of your heat loss is through your roof, windows and doors. It is not through the walls or foundation of the house. Frankly, a 2x4 framed wall with sprayed in closed cell foam insulation not only gives you plenty of R value, it also eliminates the need for a vapor
barrier. Other methods of construction from standard western framing lead to higher costs with your other contractors(plumbing and electrical).
iirc they also have one width, which might complicate multiple storey construction