A single error reporting platform for almost every popular stack/language we need, pretty easy to integrate. We're using Sentry for our projects with Django, AngularJS, Android ... and it does its job. The service integrations (Slack, github, heroku, ..) are handy and easy to setup as well, plug it into our current workflow and start playing with it in no time.
Stable, UX is good overall, with a bunch of useful features from a true error management platform. Sometime we even use it as a mini Jira for our quick clean sessions, and it works great that way.
Finally, it's opensource and free on github, for you to grab and setup your own, even make your own forked version, this seems to make Sentry an active product with active development.
Manual installation ain't that super straight forward, but not really bad, probably they encourage us to buy the SaaS paid version instead, but that would be fair enough. With the SaaS version, the price is a bit high at the moment, IMHO.
Recommended. It's easy to intergrate into almost every popular existing stack, without not much changes in the codebase. If the paid SaaS ain't ideal for you, probably give it a try with the trial one as we can always setup the free stuff after, if we really like it.
Tracking bug in all environments, for all applications in our projects. It's much like letting users to become software QA without them knowing it, and you can see the detailed stacktrace/logs in just one place, getting 'em filtered, analyzed etc .. before hand. It's kinda handy and efficient.