Looks like it'll work to me. Gotta try one of those...
I've read other posts that say they start the bottom with a ring of splits and that the wood is initially tilting in but as it gets higher, they let the ring get flatter and toward the top, the wood is eventually slanting to the outside a little bit. Not sure if that is supposed to shed water better, or what? Tilting in at the bottom would make sense for stability.
As far as laying down plastic, I've read of that being done.
You will occasionally read that it's supposed to dry wood in just a few months, but the general consensus is that it's no faster...gonna take wood a couple years to dry, especially Oak, no matter how you stack. Looks cool though. I may try one if I can figure out a fairly flat spot...