I just want to ctb fast
Am i going to die, if i just fix the rope at my neck while standing on a chair and drop the chair?
Should i jump instead?
Death is nearly certain either way. Drop hanging requires more space than you would typically find at home.
Full suspension compresses your neck arteries (and unfortunately veins and airway). Unconsciousness is quick; if you have the stomach for it, there are videos linked in the resources section. Sometimes you see some reflexive movement, but it's not a conscious death struggle--it's a bit weird, like some kind of slow zombie tai chi.
Drop hanging creates enough momentum to fracture your cervical spine (neck). It is thought, though it's unverified (you'd need a pretty fancy brain-scanning rig, I'd think) that the severing of the spine causes unconsciousness instantly. The reason there are tables are to ensure the fracture while not literally tearing your head off, which has happened in executions. The other kind of "failure" is still a full suspension, and unconsciousness is still rapid, though I expect the yank would be pretty unpleasant.