McCree’s seen a number of nerfs and buffs since Overwatch’s launch in May, but the fact remains that he’s still one of the best offensive heroes to use in competitive play right now. McCree is a great damage dealer from close to mid-range, and he’s also well-equipped to get out of sticky situations if things go south. As long as you’ve got good aim, I highly recommend using McCree for his stun ability and the ‘fan the hammer’ combo to quickly take out an enemy hero, or leave them close to death.
What you really need to get used to is the way his ultimate ability works. With Deadeye, McCree is often left vulnerable, and it’s easy to kill him in the middle of the ability. Head to higher ground before activating Deadeye, and try to get a good view of everyone on the enemy team. Once you’ve gotten used to handling Deadeye, as well as the recoil and range of the Peacemaker, you’ll be able to do some decent damage as McCree in competitive play.