I agree for the most part - except that we seem flipped on two maps.
I really disliked
Wreckage - mostly because I spawned on the side that forced me to walk into the sun flare that's placed on the horizon, so I had difficulty seeing the enemy clearly down pretty much any path I took (left, center, right). Not only that, but the flags on wreckage are placed on corridors that have sightlines spanning almost from one side of the map to the other. When the enemy team got ahead by a single point, all 5 played defense with DMRs, team shotting anyone who ventured into that corridor.
I'll need to play it more though, could have just been a couple botched matches I had on it...
Harvest, on the other hand, I had a blast with. The bases discourage camping, and the multiple paths make strategy effective. (As much strategy as you can have with randoms....) Also, it gets bonus points for the tram that runs through - a nice nod to Terminal.
Shatter I agree with you on, it feels really thrown together. One thing that really boggled my mind when playing extraction on it is the teleporters. On match start, multiple times... I would rush the teleporter to try and get the jump on my team's side base, only to find that the enemy team had made it there at the same time that I did, simply by sprinting through their cave. What good is the teleporter if it gets you there at the same time? I'm not asking for a huge advantage there, it's just that it's completely irrelevant to have it there.