* They are still trying to figure out their monetization strategy. Initially, they betted on their on-premise Enterprise version, then abandoned it. Now they are pushing their cloud version.
* Even though most of their code licensed under Apache license, some code is under their proprietary license.
* I'm sure one can get some ideas about their development directions from their issue tracker and source code, but they don't have any public product roadmap.
* Even though the product itself is technically very stable, the version compatibility leaves a lot to be desired. There are removed features and broken APIs from version to version.
* Their commercial support terms for on-premise instances don't seem to be well defined, not publicly at least.