I play on mobile so the controls are different, and tricky. You have to pull back and rotate, so you actually release on the exact opposite of where you want to shoot? I heard that on 1.5 it will be improved, will be simple tap to aim. It also shoots off behind me if I walk without unequipping so that's...something!
I have practiced with the slingshot a lot and I like it. I like to hide behind a cluster of rocks and hit enemies while I'm out of range.
There are many ammo options as well. Fruits, veggies, eggs, coal, ore, even wood. I often use berries for practice, but they don't deal much damage. Iridium ore does the most damage. Explosive ammo is pretty amazing too, more for mining than fighting. Also surprise blowing myself up, see above about how it shoots backward while I walk. Hahaha!