In my view and personal experience, the pros outweigh the cons:
* You increase the impact of your work and as a consequence also might get more citations.
* It's the right thing to do for open and reproducible research.
* You can get feedback and improve the method.
* You are still the expert on your own code. That someone picks it up, implements an idea that you also had and publishes before you is unlikely.
* I never got comments like "you could organize the code better" and don't think researchers would tend to do this.
* Via the code you can get connected to groups you haven't worked with yet.
* It's great for your CV. Companies love applicants with open-source code.