For that big of a price difference, figure them equal. The water absorption test is less with OCorn. = 0.10 and Dow= 0.30... not a biggie considering water vapor will keep the board saturated most the year anyway, lol. They used to be the same company till one branched off. Be sure to use a closed grid glue pattern on the concrete, to reduce any air leaks inadvertently made when installing it. Add some 1/2" EXP under the frame wall bottom plate for a thermal/air/capillary break. Air-seal the rim joists with canned foam using extra 2". Use a latex based paint on the drywall. Pictures when done... we love pictures!