I looked into the retrofoam product and I like what I've seen so far:
-It's slow rise. It will not blow out drywall when installed correctly.
-Applied from the inside they will have to drill a series of drywall holes to allow for over-expansion and completeness. Easy fixes.
-Low off-gassing. I got ill from the limited amount of 3M blue closed-foam I had installed.
Air leaks are much more important than R value.
An energy audit with thermal camera and blower door test will find the source of loss.
For new/open construction I also looked into:
Home | Airkrete - All Green Spray Foam Insulation!
Cementitious Foam Insulation Gets a Second Look - My Home Science
Mice can't chew through it. Fire doesn't burn it.