I started this thread, and now I'm taking the time to answer my own question, finally.
Wilderness is the best Features record thus far, hands down. I love it. Exhibit A still has a special place in my heart of course, but I think some of the song topics ("Me and the Skirts") and obvious lyics ("TtWIMtB") make it seem a little small next to Wilderness. The cliche of "maturing as a songwriter" comes to mind. SKoS is also a great record, probably above Exhibit A, but it doesn't play well live. There are, after all, several songs that have never been played live from it to my knowledge, and some, notably "Concrete," didn't have great responses when they were. I knew from the early listens that this song would play well top to bottom live.
Wilderness blows the previous records and EPs away. Musically, they're doing so many cool little things, particularly in the drumming, throughout the record that make it great on repeated listens. I love the little flourishes that Parrish (and even Don way back when) used to add to the songs, but the songs still could stand without them. The little changes that are built in now are so much more integral.
I think the other huge improvement is Matt himself. He's always been the quiet guy who gets up on stage and goes nuts when the music starts, but there's a certain rock star attitude that's more constant and more controlled (as in he's so comfortable with it that he can unleash it better now) that it's almost a true rock star swagger, though a good one. The first example is "Kids." I love the "whew"s throughout the song and the attitude that he conveys throughout the whole song. Second, he's comfortable enough to let some humor shine through. Before, it was muted within context and word choice like in "Idea of Growing Old." In another of my favorite tracks, "Fats Domino," he really unleashes the humor full-on with his spoken-word bridge. I laughed out loud when I first heard it.
As for the title, I relate it directly to "Chapter III." Matt's divorce is certainly at the forefront in the subject matter on this record, and I always took the themes to relate to the "wilderness" of the third chapter in the life of both Matt and the band--they're building a name for themselves in the wake of their major label disaster while Matt learns that someting good can come from anything, even in his personal life.