I can get 2/3 boilies at a time around 80metres in anything other than a headwind. A stick does have an advantage in that you can put in around 5 boilies in at a time rather than just one, so it can be faster than a catapult!
Straight or curved, you have to find what works best for you. I can use straight and slightly curved, but get some of the more severe curves and I am baiting the margins or my feet...