It's simple, reliable and easy to use from both administration as well as developer points of view. Support for distributed systems is great - you can easily create complex cluster setups with high availability options (HAProxy / Redis). Reliability could be improved though. I've used it in many projects at different stages of their life cycle and have never encountered any issues that would cause me to reconsider using this software so far. We needed an analytics tool which was able to process hundreds or even thousands of rows per seconds while maintaining acceptable latency. This product allowed us to do just that by providing good performance along with builtin support for various data types like JSON/XML columns etc.