usually we use pepper & salt both at a time salt is compulsory for me i use it every time while making some spicy foods pepper may or may not be used everytime.
I prefer Salt over Pepper since our country doesn't have too much spicy foods to cook and I like the taste of salt, just tangy enough to motivate my appetite. In case to case basis we use Pepper if we cook foods that has marinades or soy sauce ingredients.
I think salt .everyday i eat many salty items and those itesi like so much ,so i prefer salt.but it does not mean that peppers is bad,we use it everyday,so both of them are quite good.
salt is good for cooking usage but the overdose of salt will cause side effects such as high blood pressure but pepper is a natural recipe that willl make your cooking taste and good for health.