I think it's more instantaneous if done correctly. Honestly it would probably be my preferred method if I had access to one. I have SN and I am not looking forward to sitting and waiting while the poison courses through me and I perhaps feel the oxygen depletion in a somewhat long, drawn out process. I hope it won't be as distressing as I fear, but I also doubt it is as pleasant or peaceful as some make it out to be. But I have no other choice, what I need most out of my method now, is for it to be successful.