I got the poster map with my FLGS copy. I mean...it's nice to get something but I don't know how you'd really use it. It's double-sided, laminated, and black & white. If you're familiar with how the maps are in Ghosts of Saltmarsh, it's quite similar to those. It's actually five different locations; one is an overland map and the others are dungeons or ruins.
The thing is, it's too small to use as a battle map for minis, and both too visually bland and too revealing to give to players as a hand-out. I literally have no idea how I would use it at the table. Kinda like the physical map pack they sold separately for Dungeon of the Mad Mage that everybody hoped would be battle maps, but wasn't.
The piece is large enough that they could have had one decent battle map on each side for use with minis. But as is, the battle-maps are 1/3rd the size you'd want. Alternately, a decent overland map could go on one side, but ideally you'd want something in color & visually interesting OR something that looked like it existed in-game, like a map drawn by an NPC.
Instead they're just slightly larger, laminated versions of the utilitarian maps in the book.