The fish you're cooking should usually predicate cooking method i.e.; high fat content fish such as Salmon and Tuna can hold up to most cooking methods, while lighter fish such as Tilapia have to be cooked hard and fast...To be honest most fish need to be cooked hard and fast unless baking which works great for Walleye, Pike, and Sea Bass
Just remember fish should never be overcooked with one exception...When cooking cioppino's or boulliabase (which are both similar to stews) use a denser fish that will hold up like cod or haddock.