I have a problem though...even though I want to do what you are speaking of...lead with the hip like a bow, land on the left leg and whatnot...i kind of have a bad left knee (overuse aside from tennis or possible injury). In this vid, my leg and hip movement is not what it normally is or what i would like it to be...
It sometimes feels like i really land quite hard on the left foot...and even in my groundstrokes my split step is sometimes too hard.
I am actually trying to learn a less demanding technique on the knee without having to only use my arm, and without losing power. Not sure if thats possible...but compromise is...so somewhere I will need to compromise.
no, actually in your video your jump is just about the same height as sampras in above photos. if your knees hurt currently serving, you don't really have to jump. keep your left foot on the ground and just kick back with your right leg for balance. It might give you more consistency actually. and the loss of power is not that much actually. if you try this your stance should be turned even more left. see how your left foot is pointing when landing. closer to there for your left foot.