Like the other Essentials tile sets, The Wilderness is primarily a repackaging of previous sets. It may be entirely such; I'm not sure because I didn't already own any of the outdoor tile sets these were probably drawn from. So, setting that aside and looking at this as a standalone purchase, I'm very happy with the set and have, in fact, purchased two - though I'm not sure that's entirely necessary given the number, size and variety of the tiles here, and the rather generic nature of wilderness-based tiles.
The first thing that impressed me about The Wilderness is the relatively huge number of big 8x8 tiles. You get six of them, along with a generous six 2x8 tiles. For me, this is great; I really don't want to be laying out big, expansive outdoor encounters using scads of 4x4 or 2x4 tiles. Next, the tiles mostly depict things you will actually want to use, like roads or rivers (reverse of each other, so perhaps two sets will come in handy after all) including bends/turns, plenty of trees - both alive and dead - including three 1x1 trees to dot around your map, some graves, carts, boulders (in convenient sizes including three 1x1), water features (again including three 1x1 ponds), etc. All in all, very useful, perhaps because it is relatively generic compared to something like a cave set, with its narrow, black-edged passages or a wizard's tower with its all too familiar book-strewn tables. That begs the question: do you really need Wilderness tiles? Would not a dry erase mat do just as well? Certainly... but for that matter, a dry erase mat will do just as well for laying out anything, if that is your style of play. I would argue that something like desert is too featureless for tiles (see my Desert of Athas - Dungeon Tiles: A 4th Edition D&D Accessory review), but these Wilderness tiles do have enough character, I think, to warrant their purchase and use.
Lastly, like the two other Essentials sets currently in existence, The Wilderness makes brilliant use of the box itself, not only as a roomy storage container, but the top is a 9x12 grassy scene with a few rocks and a 4x4 tree on it. (The City has rooftops, The Dungeon has a generic dungeon floor)
Overall, I give this set highest marks, and my only reservation would be that if you own a lot of the old outdoor sets, you might not need it. The numerical breakdown of the tiles by size is listed below, and I will post some photos of the set above.
6 8x8, 6 2x8, 2 4x8, 2 5x5, 4 4x4, 8 2x4, 2 3x3, 6 2x2, 5 1x2, 7 1x1