All in all, not bad. I really like that you're keeping your head up and looking toward and through the jump, especially in the last video you posted. As Solon said, you both look very relaxed and at ease jumping.
What jumps out at me most about your position is that your feet drift ahead of you, especially (or at least more noticeably) in the videos where you're wearing the paler colored pants. I can't see your leg well enough in the last video to see if its the same there or not. Focus on keeping that shoulder/hip/heel alignment, and maybe adjust your stirrups as they may contribute to that. I do really like how you're keeping your heels down. You really look stable in the saddle. Very useful in your position, as opposed to perchy. It also looks like your thumbs tend to turn in (puppy dog hands), but again that may be the gloves and the darkness of the videos playing tricks with me.
As for your horse, he does look very relaxed, but he is pretty inverted, and could stand to be more forward. You said before that he's fast, but fast does not necessarily equal forward. Also, try to keep him in canter after the jump, maybe make a lap or two over the jump without breaking gait. When you get to courses it won't do a lot of good to have to transition between each fence; something he may be inadvertently learning by braking to trot after the jump. While your jumping looks pretty good, some good flatwork and dressage will only improve things. Take that for what its worth here, I'm a lot better versed in dressage than jumping. :wink: