Recs.
Updated
JavaScript Error Monitoring from TrackJS gives you context about what's happening in your end-users' browsers. The Telemetry timeline recreates all the application, network, and user activity that leads to an error. The stack trace processing shows you the code you need to investigate.
SpecsUpdate
Pros
Pro Engineer Support
You will always get an engineer who can understand and answer your question right away whenever you need help.
Pro Inline sourcecode snippets
Error messages and stacktraces are shown with snippets of the raw source at the location. This gives a ton of context to quickly find the error.
Cons
Con Multiple errors from the same user can bloat your metrics
No "distinct" error count. If a loop ends up inflating a single user's error count, all reports are affected. Dashboard skewed by weird outliers.
Recently (as of February 2018) sorting by "users impacted" was introduced to reduce this problem.
Recommendations
Comments
Flagged Pros + Cons
Out of Date Pros + Cons
Con Overrides window.onerror if already set
TrackJS overrides window.onerror if set, however there are plans to address this in a future release.