Six of one, half dozen of the other. How is the subfloor being put down and what type of floor covering is being installed over it?

The second story will be on 2X12s joists and will have a laminate floor. The floor on the slab will have 6mil plastic, sleepers and insulation. I hope to have loose lay vinyl and a rug.

Either should be fine as they are engineered osb subfloor

They're pretty much interchangeable. Price shop.
Casey

I prefer the Plytanium because it's true plywood whereas the Advantech is OSB. I know they are functionally the same, but I just prefer the true plywood.

Both are protected from incidental water exposure during construction; one is the plywood standard and one is the OSB standard. If the work will be under a roof why pay a premium for either of them?

The lumber yard felt that since the work will be done in winter and spring for the difference in money ( less then $100) the extra protection of getting the material wet when building the dormer it was worth it. I agree that this work should not get wet but I worry if the dormer would take longer then expected. I thought the OSB would be cheaper then the plywood but the difference is $1 per board so it is insignificant. 2 local lumberyards disagree which is better but both agreed both are good.
Thanks for all of the responses