Jumping takes a lot more courage to do IMO. Just looking down scares me enough not to do it. Also, you need to find a suitable spot to do the jump, which can be quite difficult depending on location and living situation. Also, if the jump isn't fatal, their is a high chance their will be permanent damage, which isn't fun.
With SN, it's quite easy to prepare, depending on your country. Also, taking a drink is a lot easier than making that jump. You can also spend as much time amping yourself up to take that drink, whereas with jumping, you can't wait too long or you'll get caught by do-gooders. The most enticing thing with SN is that the effects are pretty much always entirely reversible. If you're found/"rescued" you'll be pumped with the antidote, and back to normal within a week, if posts here are to be believed. Same can't be said for jumping.
SN is my preferred method. However, if you gag, or are prone to puking easily, it's most likely not for you.