While implementing selenium automation for one of the projects, we have evaluated casperjs, phantomjs, selenium and now selenium with chromedriver.
Of all of them chromedriver seems most robust and is the current favorite. Here are my reasons for using chromedriver:

1. Easy installation
2. phantomjs leaves too many stale processes and causes memory leaks. Not faced this issue with chromedriver
3. Requires centos 7. It has compatibility issues with centos 6
4. Multiple ChromeOptions() for finer control
5. Allows for automating browser download via a button click and 'save as' dialog box. phantomjs based selenium was unable to do it
6. All selenium WebDriver methods are available
7. Ongoing support. Supported and managed by Google - http://chromedriver.chromium.org/help This has allowed for creation of powerful web crawlers and bots!