I, like most people, ran Tough as Nails before switching to this due to increasing bugs in TAN, some things I'm still wishing I had still though is the ability to fill canteens from the rain collectors and that filling the canteen from rain gave purified water instead of regular water, just thinking that if I can drink rain with my hands is safe then the water I collect in my canteen should be safe to drink too.

Unrelated to canteens though, if somehow you could bring back how TAN tapered off the temperatures the more underground you were instead of just cutting off entirely at a certain point. Being able to go inside a home or cave to lessen the affects of temperature a little would help a lot especially in the early game.