In the company’s product forums, the Chrome team has proactively provided answers to some concerns they anticipate to be raised, including whether or not the company will collect and store browsing history with this extension (answer: no), and whether or not the extension will impact a user’s browser performance (again, the answer is no). “The only data this extension sends to Google is when these infrequent events occur and your survey responses,” the team states in the post. Keep in mind that if you use other Google services like Search and Gmail, they probably already have a lot of data about you anyway.
There are no incentives for downloading and installing the extension other than, perhaps, improvements that Google can make to Chrome as a result of the data they collect from users of the extension. One suggestion I can provide right off the bat that would improve my experience using Chrome? Make it less of a notoriously significant CPU hog.