I don't own the Kite, but I have used my mantis on every sit this year. I am still figuring it out. I found a lot of the thoughts and experiences you had were similar to mine. I have had that "falling feeling" with my mantis as well. It happened to me the fist time this past weekend and it scared the begeezies out of me lol.
I am not a fan of the buckle, and the funny thing is I got on here to post a thread asking for an alternative and then saw this post. I don't like the metal clanking in the strap adjustment. I also wear mine in and feel that it is lacking a little there. I used the set of loops they sent with the saddle to make my straps more secure(little metal piece with two eyes you run the slack of the belt through to make it more stationary) and it helps it stay still, but it makes it a bugger to adjust if you need too. I have thought about putting a quality buckle on there but i'm not sure which way to go there.
I have also noticed that it doesn't have much cup to it. The comfort isn't an issue, but I do have to slide it down occasionally. I do believe my bridge is a little too long, but I don't believe it to be a problem. The saddle has been comfortable to me thus far. I don't have many complaints about it.
I also don't understand why the micro adjusters were included. I understand the modularity of them, but I can't decide if it is just another way to get money from them or what. I would like to see them come with the saddle for the same price, especially since there isn't much too them.
One other thing I have also noticed is one of my SYS haulers keeps coming out of the molle loops some how. It happened 3 times this week.
I would like for the saddle to be more secure and able to be cinched all the way up while walking in. When you put a couple ropes in one hauler and tree accessories in the other hauler it is very prone to slide all the way down on you!