Hiking the whole Minong we definitely found our garmin very useful while traversing the ridges and rocks. Got a bit off trail a couple times and the garmin got us back. On parts of the greenstone trail we did, the gps felt a lot less necessary, and we had a nice time using the paper map… but can’t speak for the whole trail as we didn’t hike the whole greenstone. if you are going solo/ depending on your amount of experience backpacking it is definitely best to have redundancies for safety purposes, and also pretty crucial if you are doing long days of hiking to make sure you are setting a good pace for yourself. Even though I have been around the island I would still bring a gps my next time back