I almost never use guthans anymore, only on slayer tasks where the monsters hit hard and thus require a few bank trips to finish a large task (i.e. hell hounds in taverly dungeon). However, it usually isnt worth the loss in damage you get from swapping off your black mask, whip and defender. Banking will almost always take less time to do then the time you lose by swapping back and forth between guthans. Bones to peaches probably loses you less time but it still isn't worth it in most situations like those where you get no bone drops or monsters that hit you for more than 8 hitpoints on average each. They are a good substitute for guthans on tasks like dust devils, which are in the middle of nowhere and dont require too much food. Outside of slayer you obviously lose less using guthans due to not being able to use a black mask. The same as above still stands though, you still have to swap off your whip and defender to heal and this can be a little irritating at times. Though you could always try the risky afk training at bandits in the desert with your spear constantly equiped, but I've heard of a few stories where this has resulted in banning. I typically use guthans for the sake of being to lazy to bank on a long slayer task even though its faster to use food, especially if the monsters are in a obnoxious location like brimhaven dungeon. Guthans is useful in this situation just to save a bit of effort for a slight reduction in speed. Similar to this, long training trips that don't involve pest control have a big use for lazy use of guthans aswell, particularily at the dagganoths under the lighthouse. Though daggs drop plenty of bones and bones to peaches is plenty to heal in this situation. In all I have to say the bones to peaches is useful mainly for situations where you get bones and the monsters aren't too tough. Guthans is better is the monsters are strong enough to do more than 8 damage to you on average. Bones to peaches is probably more useful in slayer for making a task as fast as possible as opposed to you usually losing more time by using guthans then you would by banking instead. Finally, guthans is better in a situation where you dont want to put too much effort into healing i.e. afk training or when a slayer task is too out of the way and dosent drop bones or is too tough for bones to peaches to handle.
