I always stand, cuz thats how I practice. If I'm gonna hunt out of my blind I practice shooting sitting down..but in a treestand I like to stand.
Actually though, the first arrow I ever let go at a deer was from a sitting position in my treestand. Lets just say it didnt work out..
Ever since then I've made sure I'm alert and ready so that I have time to stand up in the stand before the deer are right on top of me.
Just feels better to shoot standingimo... Plus its easier to bend at the waist so that my point of aim is not messed up. Learned that lesson..I guess I dont have as much confidence yet shooting at downward angles while sitting