what's AdvanTech subfloor?

I though AdvanTech is a company but when I read more on the internet. I think I am not quite right. It looks like that AdvanTech is something like plywood but better than plywood in moisture/wet environment. Anybody here knows details about AdvanTech?

AdvanTech is a somewhat stiffer & flatter than average 23/32" OSB subfloor product made by Huber Engineered Woods (the manufacturer of ZIP System weather resistant sheathing and other products.)

Dana, should we "upgrade" to AdvanTech or stay with the plywood in our basement project?

The advantages for AvanTech apply primarily to subfloors spanning joists, where the extra rigidity and flatness buys you something. For the basement project the half-inch ply is already supported by the XPS and concrete- it's already pretty rigid (as rigid as your concrete, less the elastic depression of the XPS, which is still pretty stiff.) There's no call for any subfloor-rated product in this application, since structural rigidity beyond the stiffness of the slab just isn't necessary to keep it from flexing the way it is when spanning joists.

Advantech is flat, square, and heavy! I've used it in my remodeling, but as Dana said, probably no good reason to spend more for it in your application. They also make it in other thicknesses (I think up to 1-1/8"). It's big advantage is that it doesn't swell up on a jobsite if the house doesn't get closed in and you get a big rainstorm like some OSB does. You can read more about it on the Huber website, if you wish.