Splunk Enterprise Reviews

Summary: Although Splunk comes at a premium and requires efforts to master, its excellence in log analytics, monitoring, data visualization and report generation makes it worth the price and effort.

Positive: Customizable dashboards.
Can consume multiple log sources.
Extensive and deep search feature.
Search Queries can be converted to apps.
Alert system based on log data.

Negative: Steep learning curve.
Search can be slow for huge logs.
Expensive.

Summary: Make sure you know what types of analytics your business cares about. If you only need some metrics and not detailed records of every incident, Splunk probably isn't for you.

Positive: Splunk is top of the line for logging. But that means paying a lot every month, and keeping a lot of data, so make sure you actually need detailed logging.
If you do, Splunk has a lot of built in functions to analyze your logging data and help your business be more insightful.

Negative: If you only need some of the metrics and not all the logs, getting Splunk means you're wasting money and overengineering your analytics process. You can use an open source metrics system like Prometheus instead if that's what you need. It's also super easy to accidentally get false alerts on Splunk, and that will not make your oncall engineers happy.