I used Icynene in my place.
I have a house that was built in 1922. I used it to insulate the ring joists where air infiltration was a huge problem. (Fibre glass will not stop air infiltration - AKA drafts.)
I was very happy with the results.
The BASF is a superior insulator, however, I liked the Icynene because it is not toxic, nor does it continue to off gas. With the BASF, you need to move out of your house "for a day"
A day? What, does this stuff know how many hours there are in a day?
The Icynene has the same R value as fibre glass, it also requires a vapour barrier be used (the BASF - you can get away without a vapour barrier.) It seals against drafts, so as far as it goes, you have an air tight wall cavity with the same insulation value as batt.
Being in the Construction field for oh, going on 30 years now (started at 15 stripping base boards in the summers for $2.45 an hour!), I do feel that I know a thing or two about houses (though I am still learning.) The fact of the matter is that about 70% of your heat loss is through the roof. Most attics are insulated with blown in fibre glass, or batt fibre glass. The foam is used in walls, over garages, etc.
The graph for heat loss vs. R value is not a straight line. In short, the first R-6 does more to insulate your wall than the subsequent R-12 will do. In other words, the first inch of styrofoam insulation in your wall does more to keep the heat in than the next 3" will do.
So, the Icynene gives good insulation with no toxic question marks, and it is as effective in sealing drafts as the BASF is.
It's a no brainer.
