When comparing Airbrake vs Raygun, the Slant community recommends Airbrake for most people. In the question“What are the best JavaScript client-side error logging services?” Airbrake is ranked 7th while Raygun is ranked 9th. The most important reason people chose Airbrake is:
Airbrake.io boasts a beautiful user interface which gives easy access to features such as intelligent error grouping and application insights, session details and backtraces. All these allow you to squash those bugs at a much faster pace.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Easy to use UI
Airbrake.io boasts a beautiful user interface which gives easy access to features such as intelligent error grouping and application insights, session details and backtraces. All these allow you to squash those bugs at a much faster pace.
Pro Airbrake errors can be self-hosted on Errbit
Errbit is a self-hosted error catcher for Airbrake. It allows keeping errors off Airbrake's servers by using Airbrake's error tracking tools to send error logs to your own ErrBit based web service. Useful for when errors contain sensitive client data.
Pro Asynchronous error tracking script
By including Airbrake's client side error tracking JS into your code, you won't have to worry about it affecting your page load times at all. Since the library loads asynchronously, which means it won't cause painful delays for your site's visitors.
Pro Easy integration with other applications
Airbrake integrates easily with Github, Hipchat, Asana and a number of other services, which can be viewed here. Also if you've got a custom app you'd like to integrate into Airbrake, you can use Airbrake's public API or there web hooks functionality to your advantage.
Pro Allows leaving comments on issues
It's possible to comment on issues. Great for coordinating if and how exceptions should be handled within a team.
Pro Exceptions are grouped
Raygun groups similar exceptions together displaying the number of occurences so that there's no need to deal with each instance of the error separately.
Pro Daily digest emails
Raygun can send a summary of all error that have happened over the day.
Pro Email notifications
Raygun can be set up to send email notifications as soon as exceptions occur.
Cons

Con Non-free / propritary software
Airbrake is non-free software, so it cannot be self-hosted, audited, or improved upon by the community. Your data is insecure - open to be read by Airbrake Inc, and if they shut down you will be unable to continue using the software.
Con No integrations on the free plan
Con Inefficient UI
