Keep in mind that expanded polystyrene (EPS), which is what InSoFast is composed of, has a relatively low R-value per inch vs. extruded polystyrene (XPS) board. So to meet minimum International Energy Conservation Code (IECC) guidelines, which will eventually cover most jurisdictions, you will usually require multiple thicknesses, thus reducing floor space, and raising comparative costs.

As well, you will need more fasteners to adhere it to the foundation wall than using, say 4'x8' panels of board insulation.

Finally, as the drywall is attached directly to the InSoFast, it looks like the system must be plumb to the wall, or the finished drywall will reflect that. In practice, poured walls will be very uneven which is no problem when the framing is separate. This proprietary system would seem to better suited to unit masonry walls.

Ah the forever battle of eps vs xps for basements.

We just used it in our basement. Worked great!

I used it about a year ago in a basement bedroom that flooded slightly due to a detached downspout. The pre-existing finished walls were concrete block, with some sort of paper vapor barrier, then thin furring strips (1x2) and then drywall, with no insulation whatsoever. I followed the directions for installation they recommend: First painting the block walls with drylock extreme paint, then adhering the panel to that using the specific polyurethane adhesive they recommend, then screwing the drywall to the panels.

I'm very happy with how it turned out, especially because after determining that the room would require 2 boxes of the panels (or maybe slightly more), which come 5 to a box (IIRC), I found a craigslist listing for 3 boxes of the panels for approximately the usual retail price of one box. Then when I went to pick them up, I found that the craigslist boxes were older, from a time when the a box contained ten 2' by 4' panels.

So while their usual price for the panels makes it "about the same price" as building a stud wall and insulating it, the cost for me was substantially less.