From what I've seen so far
Hanging:
Pros
-quicker, if done right.
-"painless" because of unconsciousness
-not expensive, only requires rope or something strong and long like it and strong place of suspension.
-Can be done pretty much wherever you choose.
-doesn't require much set up other than a few test tugs and a good slipknot
-a good slipknot will help bail you out if you change your mind
Cons
-You NEED to know where to place the rope exactly on your neck for it to work, otherwise it'll be agony.
-if you mess up tying the slipknot you won't be able to get yourself down to bail out and you'll feel yourself choking for what could be minutes.
-if survived braindead and vegetable state is highly more likely.
Sn:
Pros
-even a small amount is able to be fatal, guaranteed ctb if done correctly
-"painless" again because of unconsciousness
-Can be done just lying in bed
-Have time to throw it up and call for help if you change your mind.
-longish shelf life
Cons
-More expensive to get, especially shipping depending on your source and country
-if doing the full method including the drugs to be taken with it for full effectiveness that can also be tedious to acquire and set up
-if you don't know the purity, it can be tedious to test
-likely to throw it up and survive
-longer wait time to work
There's definitely more to think of but that's just quickly off the top of my head. Honestly things can go wrong with both methods but I definitely wouldn't want to go wrong with hanging cause it sounds traumatic as hell.