Chicken wire keeps chickens in (or out depending on the application). It is not a deterrent for predators. Hardware cloth is used to keep predators out. So no, you don't use one instead of the other. You use each where it is appropriate for the job it is intended to do. If you only want to buy one type, get hardware cloth. It'll be overkill containing the chickens, but it'll keep them safer from predators.
My run is 16x32 and is just chicken wire on all sides and the top. I have 6 3' long windows in the coop that are chicken wire also. But I have 5 dogs on the property that keep all large predators away. They catch and kill everything but snakes. They let me know if a snake is in the area but they won't get close enough to kill them. In over 2 years nothing has gotten in the coop, except snakes.
Over twenty years, hardware cloth, backed up by woven wire on the bottom three or four feet, will protect your birds better. Most people don't have a pack of dogs that patrol 24/7, so they must make other provisions. Mary
Very true. I learned my lesson building my outdoor cat enclosure, used chicken wire at first; I didn't know any better. It took only five minutes from the time my room mate left until I got home for the dogs down the street to rip a hole through the chicken wire and tear part of it from the frame. Also, stapling any fence alone won't secure fence I've found out through the same incident. I have since reinforced it by screwing furlong strips sandwiching some welded wire fencing to the frame; won't make the same mistake with my chickens.